path: root/doc/rfc/rfc5416.txt

Network Working Group                                    P. Calhoun, Ed.
Request for Comments: 5416                           Cisco Systems, Inc.
Category: Standards Track                             M. Montemurro, Ed.
                                                      Research In Motion
                                                         D. Stanley, Ed.
                                                          Aruba Networks
                                                              March 2009


  Control and Provisioning of Wireless Access Points (CAPWAP) Protocol
                        Binding for IEEE 802.11

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (c) 2009 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents in effect on the date of
   publication of this document (http://trustee.ietf.org/license-info).
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.









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Abstract

   Wireless LAN product architectures have evolved from single
   autonomous access points to systems consisting of a centralized
   Access Controller (AC) and Wireless Termination Points (WTPs).  The
   general goal of centralized control architectures is to move access
   control, including user authentication and authorization, mobility
   management, and radio management from the single access point to a
   centralized controller.

   This specification defines the Control And Provisioning of Wireless
   Access Points (CAPWAP) Protocol Binding Specification for use with
   the IEEE 802.11 Wireless Local Area Network protocol.

Table of Contents

   1. Introduction ....................................................4
      1.1. Goals ......................................................5
      1.2. Conventions Used in This Document ..........................5
      1.3. Terminology ................................................5
   2. IEEE 802.11 Binding .............................................7
      2.1. CAPWAP Wireless Binding Identifier .........................7
      2.2. Split MAC and Local MAC Functionality ......................7
           2.2.1. Split MAC ...........................................7
           2.2.2. Local MAC ..........................................12
      2.3. Roaming Behavior ..........................................15
      2.4. Group Key Refresh .........................................16
      2.5. BSSID to WLAN ID Mapping ..................................17
      2.6. CAPWAP Data Channel QoS Behavior ..........................18
           2.6.1. IEEE 802.11 Data Frames ............................18
                  2.6.1.1. 802.1p Support ............................19
                  2.6.1.2. DSCP Support ..............................19
           2.6.2. IEEE 802.11 MAC Management Messages ................21
      2.7. Run State Operation .......................................21
   3. IEEE 802.11 Specific CAPWAP Control Messages ...................21
      3.1. IEEE 802.11 WLAN Configuration Request ....................22
      3.2. IEEE 802.11 WLAN Configuration Response ...................23
   4. CAPWAP Data Message Bindings ...................................23
   5. CAPWAP Control Message Bindings ................................25
      5.1. Discovery Request Message .................................25
      5.2. Discovery Response Message ................................25
      5.3. Primary Discovery Request Message .........................25
      5.4. Primary Discovery Response Message ........................26
      5.5. Join Request Message ......................................26
      5.6. Join Response Message .....................................26
      5.7. Configuration Status Request Message ......................26
      5.8. Configuration Status Response Message .....................27
      5.9. Configuration Update Request Message ......................27



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      5.10. Station Configuration Request ............................28
      5.11. Change State Event Request ...............................28
      5.12. WTP Event Request ........................................28
   6. IEEE 802.11 Message Element Definitions ........................29
      6.1. IEEE 802.11 Add WLAN ......................................29
      6.2. IEEE 802.11 Antenna .......................................35
      6.3. IEEE 802.11 Assigned WTP BSSID ............................36
      6.4. IEEE 802.11 Delete WLAN ...................................37
      6.5. IEEE 802.11 Direct Sequence Control .......................37
      6.6. IEEE 802.11 Information Element ...........................38
      6.7. IEEE 802.11 MAC Operation .................................39
      6.8. IEEE 802.11 MIC Countermeasures ...........................41
      6.9. IEEE 802.11 Multi-Domain Capability .......................42
      6.10. IEEE 802.11 OFDM Control .................................43
      6.11. IEEE 802.11 Rate Set .....................................44
      6.12. IEEE 802.11 RSNA Error Report From Station ...............44
      6.13. IEEE 802.11 Station ......................................46
      6.14. IEEE 802.11 Station QoS Profile ..........................47
      6.15. IEEE 802.11 Station Session Key ..........................48
      6.16. IEEE 802.11 Statistics ...................................50
      6.17. IEEE 802.11 Supported Rates ..............................54
      6.18. IEEE 802.11 Tx Power .....................................54
      6.19. IEEE 802.11 Tx Power Level ...............................55
      6.20. IEEE 802.11 Update Station QoS ...........................56
      6.21. IEEE 802.11 Update WLAN ..................................57
      6.22. IEEE 802.11 WTP Quality of Service .......................61
      6.23. IEEE 802.11 WTP Radio Configuration ......................63
      6.24. IEEE 802.11 WTP Radio Fail Alarm Indication ..............65
      6.25. IEEE 802.11 WTP Radio Information ........................66
   7. IEEE 802.11 Binding WTP Saved Variables ........................67
      7.1. IEEE80211AntennaInfo ......................................67
      7.2. IEEE80211DSControl ........................................67
      7.3. IEEE80211MACOperation .....................................67
      7.4. IEEE80211OFDMControl ......................................67
      7.5. IEEE80211Rateset ..........................................67
      7.6. IEEE80211TxPower ..........................................67
      7.7. IEEE80211QoS ..............................................68
      7.8. IEEE80211RadioConfig ......................................68
   8. Technology Specific Message Element Values .....................68
      8.1. WTP Descriptor Message Element, Encryption
           Capabilities Field ........................................68
   9. Security Considerations ........................................68
      9.1. IEEE 802.11 Security ......................................68
   10. IANA Considerations ...........................................70
      10.1. CAPWAP Wireless Binding Identifier .......................70
      10.2. CAPWAP IEEE 802.11 Message Types .........................70
      10.3. CAPWAP Message Element Type ..............................70
      10.4. IEEE 802.11 Key Status ...................................71



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      10.5. IEEE 802.11 QoS ..........................................71
      10.6. IEEE 802.11 Auth Type ....................................71
      10.7. IEEE 802.11 Antenna Combiner .............................71
      10.8. IEEE 802.11 Antenna Selection ............................72
      10.9. IEEE 802.11 Session Key Flags ............................72
      10.10. IEEE 802.11 Tagging Policy ..............................72
      10.11. IEEE 802.11 WTP Radio Fail ..............................72
      10.12. IEEE 802.11 WTP Radio Type ..............................73
      10.13. WTP Encryption Capabilities .............................73
   11. Acknowledgments ...............................................73
   12. References ....................................................73
      12.1. Normative References .....................................73
      12.2. Informative References ...................................75

1.  Introduction

   The CAPWAP protocol [RFC5415] defines an extensible protocol to allow
   an Access Controller to manage wireless agnostic Wireless Termination
   Points.  The CAPWAP protocol itself does not include any specific
   wireless technologies; instead, it relies on a binding specification
   to extend the technology to a particular wireless technology.

   This specification defines the Control And Provisioning of Wireless
   Access Points (CAPWAP) Protocol Binding Specification for use with
   the IEEE 802.11 Wireless Local Area Network protocol.  Use of CAPWAP
   control message fields, new control messages, and message elements
   are defined.  The minimum required definitions for a binding-specific
   Statistics message element, Station message element, and WTP Radio
   Information message element are included.

   Note that this binding only supports the IEEE 802.11-2007
   specification.  Of note, this binding does not support the ad hoc
   network mode defined in the IEEE 802.11-2007 standard.  This
   specification also does not cover the use of data frames with the
   four-address format, commonly referred to as Wireless Bridges, whose
   use is not specified in the IEEE 802.11-2007 standard.  This protocol
   specification does not currently officially support IEEE 802.11n.
   That said, the protocol does allow a WTP to advertise support for an
   IEEE 802.11n radio; however, the protocol does not allow for any of
   the protocol's additional features to be configured and/or used.  New
   IEEE protocol specifications published outside of this document
   (e.g., IEEE 802.11v, IEEE 802.11r) are also not supported through
   this binding, and in addition to IEEE 802.11n, must be addressed
   either through a separate CAPWAP binding, or an update to this
   binding.






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RFC 5416        CAPWAP Protocol Binding for IEEE 802.11       March 2009


   In order to address immediate market needs for standards still being
   developed by the IEEE 802.11 standards body, the WiFi Alliance
   created interim pseudo-standards specifications.  Two such
   specifications are widely used in the industry, namely the WiFi
   Protect Access [WPA] and the WiFi MultiMedia [WMM] specifications.
   Given their widespread adoption, this CAPWAP binding requires the use
   of these two specifications.

1.1.  Goals

   The goals of this CAPWAP protocol binding are to make the
   capabilities of the CAPWAP protocol available for use in conjunction
   with IEEE 802.11 wireless networks.  The capabilities to be made
   available can be summarized as:

   1. To centralize the authentication and policy enforcement functions
      for an IEEE 802.11 wireless network.  The AC may also provide
      centralized bridging, forwarding, and encryption of user traffic.
      Centralization of these functions will enable reduced cost and
      higher efficiency by applying the capabilities of network
      processing silicon to the wireless network, as in wired LANs.

   2. To enable shifting of the higher-level protocol processing from
      the WTP.  This leaves the time-critical applications of wireless
      control and access in the WTP, making efficient use of the
      computing power available in WTPs that are subject to severe cost
      pressure.

   The CAPWAP protocol binding extensions defined herein apply solely to
   the interface between the WTP and the AC.  Inter-AC and station-to-AC
   communication are strictly outside the scope of this document.

1.2.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

1.3.  Terminology

   This section contains definitions for terms used frequently
   throughout this document.  However, many additional definitions can
   be found in [IEEE.802-11.2007].

   Access Controller (AC): The network entity that provides WTP access
   to the network infrastructure in the data plane, control plane,
   management plane, or a combination therein.




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   Basic Service Set (BSS): A set of stations controlled by a single
   coordination function.

   Distribution: The service that, by using association information,
   delivers medium access control (MAC) service data units (MSDUs)
   within the distribution system (DS).

   Distribution System Service (DSS): The set of services provided by
   the distribution system (DS) that enable the medium access control
   (MAC) layer to transport MAC service data units (MSDUs) between
   stations that are not in direct communication with each other over a
   single instance of the wireless medium (WM).  These services include
   the transport of MSDUs between the access points (APs) of basic
   service sets (BSSs) within an extended service set (ESS), transport
   of MSDUs between portals and BSSs within an ESS, and transport of
   MSDUs between stations in the same BSS in cases where the MSDU has a
   multicast or broadcast destination address, or where the destination
   is an individual address but the station sending the MSDU chooses to
   involve the DSS.  DSSs are provided between pairs of IEEE 802.11
   MACs.

   Integration: The service that enables delivery of medium access
   control (MAC) service data units (MSDUs) between the distribution
   system (DS) and an existing, non-IEEE 802.11 local area network (via
   a portal).

   Station (STA): A device that contains an IEEE 802.11 conformant
   medium access control (MAC) and physical layer (PHY) interface to the
   wireless medium (WM).

   Portal: The logical point at which medium access control (MAC)
   service data units (MSDUs) from a non-IEEE 802.11 local area network
   (LAN) enter the distribution system (DS) of an extended service set
   (ESS).

   WLAN: In this document, WLAN refers to a logical component
   instantiated on a WTP device.  A single physical WTP may operate a
   number of WLANs.  Each Basic Service Set Identifier (BSSID) and its
   constituent wireless terminal radios is denoted as a distinct WLAN on
   a physical WTP.

   Wireless Termination Point (WTP): The physical or network entity that
   contains an IEEE 802.11 RF antenna and wireless PHY to transmit and
   receive station traffic for wireless access networks.







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RFC 5416        CAPWAP Protocol Binding for IEEE 802.11       March 2009


2.  IEEE 802.11 Binding

   This section describes use of the CAPWAP protocol with the IEEE
   802.11 Wireless Local Area Network protocol, including Local and
   Split MAC operation, Group Key Refresh, Basic Service Set
   Identification (BSSID) to WLAN Mapping, IEEE 802.11 MAC management
   frame Quality of Service (Qos) tagging and Run State operation.

2.1.  CAPWAP Wireless Binding Identifier

   The CAPWAP Header, defined in Section 4.3 of [RFC5415] requires that
   all CAPWAP binding specifications have a Wireless Binding Identifier
   (WBID) assigned.  This document, which defines the IEEE 802.11
   binding, uses the value one (1).

2.2.  Split MAC and Local MAC Functionality

   The CAPWAP protocol, when used with IEEE 802.11 devices, requires
   specific behavior from the WTP and the AC to support the required
   IEEE 802.11 protocol functions.

   For both the Split and Local MAC approaches, the CAPWAP functions, as
   defined in the taxonomy specification [RFC4118], reside in the AC.

   To provide system component interoperability, the WTP and AC MUST
   support 802.11 encryption/decryption at the WTP.  The WTP and AC MAY
   support 802.11 encryption/decryption at the AC.

2.2.1.  Split MAC

   This section shows the division of labor between the WTP and the AC
   in a Split MAC architecture.  Figure 1 shows the separation of
   functionality between CAPWAP components.


















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RFC 5416        CAPWAP Protocol Binding for IEEE 802.11       March 2009


        Function                               Location
            Distribution Service                      AC
            Integration Service                       AC
            Beacon Generation                         WTP
            Probe Response Generation                 WTP
            Power Mgmt/Packet Buffering               WTP
            Fragmentation/Defragmentation             WTP/AC
            Assoc/Disassoc/Reassoc                    AC

       IEEE 802.11 QoS
            Classifying                               AC
            Scheduling                                WTP/AC
            Queuing                                   WTP

       IEEE 802.11 RSN
            IEEE 802.1X/EAP                           AC
            RSNA Key Management                       AC
            IEEE 802.11 Encryption/Decryption         WTP/AC

     Figure 1: Mapping of 802.11 Functions for Split MAC Architecture

   In a Split MAC Architecture, the Distribution and Integration
   services reside on the AC, and therefore all user data is tunneled
   between the WTP and the AC.  As noted above, all real-time IEEE
   802.11 services, including the Beacon and Probe Response frames, are
   handled on the WTP.

   All remaining IEEE 802.11 MAC management frames are supported on the
   AC, including the Association Request frame that allows the AC to be
   involved in the access policy enforcement portion of the IEEE 802.11
   protocol.  The IEEE 802.1X [IEEE.802-1X.2004], Extensible
   Authentication Protocol (EAP) [RFC3748] and IEEE Robust Security
   Network Association (RSNA) Key Management [IEEE.802-11.2007]
   functions are also located on the AC.  This implies that the
   Authentication, Authorization, and Accounting (AAA) client also
   resides on the AC.

   While the admission control component of IEEE 802.11 resides on the
   AC, the real-time scheduling and queuing functions are on the WTP.
   Note that this does not prevent the AC from providing additional
   policy and scheduling functionality.

   Note that in the following figure, the use of '( - )' indicates that
   processing of the frames is done on the WTP.  This figure represents
   a case where encryption services are provided by the AC.






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RFC 5416        CAPWAP Protocol Binding for IEEE 802.11       March 2009


             Client                      WTP                         AC

                      Beacon
             <-----------------------------
                   Probe Request
             ----------------------------( - )------------------------->
                   Probe Response
             <-----------------------------
                              802.11 AUTH/Association
             <--------------------------------------------------------->
                                        Station Configuration Request
                                          [Add Station (Station MAC
                                          Address), IEEE 802.11 Add
                                          Station (WLAN ID), IEEE
                                          802.11 Session Key(Flag=A)]
                                            <-------------------------->
                    802.1X Authentication & 802.11 Key Exchange
             <--------------------------------------------------------->
                                        Station Configuration Request
                                          [Add Station(Station MAC
                                          Address), IEEE 802.11 Add
                                          Station (WLAN ID), IEEE 802.11
                                          Station Session Key(Flag=C)]
                                            <-------------------------->
                               802.11 Action Frames
             <--------------------------------------------------------->
                                   802.11 DATA (1)
             <---------------------------( - )------------------------->

                     Figure 2: Split MAC Message Flow

   Figure 2 provides an illustration of the division of labor in a Split
   MAC architecture.  In this example, a WLAN has been created that is
   configured for IEEE 802.11, using 802.1X-based end user
   authentication and Advanced Encryption Standard-Counter Mode with
   CBC-MAC Protocol (AES-CCMP) link layer encryption (CCMP, see
   [FIPS.197.2001]).  The following process occurs:

   o  The WTP generates the IEEE 802.11 Beacon frames, using information
      provided to it through the IEEE 802.11 Add WLAN (see Section 6.1)
      message element, including the Robust Security Network Information
      Element (RSNIE), which indicates support of 802.1X and AES-CCMP.

   o  The WTP processes the Probe Request frame and responds with a
      corresponding Probe Response frame.  The Probe Request frame is
      then forwarded to the AC for optional processing.





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   o  The WTP forwards the IEEEE 802.11 Authentication and Association
      frames to the AC, which is responsible for responding to the
      client.

   o  Once the association is complete, the AC transmits a Station
      Configuration Request message, which includes an Add Station
      message element, to the WTP (see Section 4.6.8 in [RFC5415]).  In
      the above example, the WLAN was configured for IEEE 802.1X, and
      therefore the IEEE 802.11 Station Session Key is included with the
      flag field's 'A' bit set.

   o  If the WTP is providing encryption/decryption services, once the
      client has completed the IEEE 802.11 key exchange, the AC
      transmits another Station Configuration Request message, which
      includes:

      -  An Add Station message element.

      -  An IEEE 802.11 Add Station message element, which includes the
         WLAN Identifier with which the station has associated.

      -  An IEEE 802.11 Station Session Key message element, which
         includes the pairwise encryption key.

      -  An IEEE 802.11 Information Element message element, which
         includes the Robust Security Network Information Element
         (RSNIE) to the WTP, stating the security policy to enforce for
         the client (in this case AES-CCMP).

   o  If the WTP is providing encryption/decryption services, once the
      client has completed the IEEE 802.11 key exchange, the AC
      transmits another Station Configuration Request message, which
      includes:

      -  An Add Station message element.

      -  An IEEE 802.11 Add Station message element, which includes the
         WLAN Identifier with which the station has associated.

      -  An IEEE 802.11 Station Session Key message element, which
         includes the pairwise encryption key.

      -  An IEEE 802.11 Information Element message element, which
         includes the Robust Security Network Information Element
         (RSNIE) to the WTP, stating the security policy to enforce for
         the client (in this case AES-CCMP).





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   o  If the AC is providing encryption/decryption services, once the
      client has completed the IEEE 802.11 key exchange, the AC
      transmits another Station Configuration Request message, which
      includes:

      -  An Add Station message element.

      -  An IEEE 802.11 Add Station message element, which includes the
         WLAN Identifier with which the station has associated.

      -  An IEEE 802.11 Station Session Key message element with the
         flag field's 'C' bit enabled (indicating that the AC will
         provide crypto services).

   o  The WTP forwards any IEEE 802.11 Management Action frames received
      to the AC.

   o  All IEEE 802.11 station data frames are tunneled between the WTP
      and the AC.

   Note that during the EAP over LAN (EAPOL)-Key exchange between the
   Station and the AC, the Receive Sequence Counter (RSC) field for the
   Group Key (GTK) needs to be included in the frame.  The value of zero
   (0) is used by the AC during this exchange.  Additional details are
   available in Section 9.1.

   The WTP SHALL include the IEEE 802.11 MAC header contents in all
   frames transmitted to the AC.

   When 802.11 encryption/decryption is performed at the WTP, the WTP
   MUST decrypt the uplink frames, MUST set the Protected Frame field to
   0, and MUST make the frame format consistent with that of an
   unprotected 802.11 frame prior to transmitting the frames to the AC.
   The fields added to an 802.11 protected frame (i.e., Initialization
   Vector/Extended Initialization Vector (IV/EIV), Message Integrity
   Code (MIC), and Integrity Check Value (ICV)) MUST be stripped off
   prior to transmission from the WTP to AC.  For downlink frames, the
   Protected Frame field MUST be set to 0 by the AC as the frame being
   sent is unencrypted.  The WTP MUST apply the required protection
   policy for the WLAN, and set the Protected Frame field on
   transmission over the air.  The Protected Frame field always needs to
   accurately indicate the status of the 802.11 frame that is carrying
   it.

   When 802.11 encryption/decryption is performed at the AC, the WTP
   SHALL NOT decrypt the uplink frames prior to transmitting the frames
   to the AC.  The AC and WTP SHALL populate the IEEE 802.11 MAC header
   fields as described in Figure 3.



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           MAC header field        Location
                   Frame Control:
                           Version         AC
                           ToDS            AC
                           FromDS          AC
                           Type            AC
                           SubType         AC
                           MoreFrag        WTP/AC
                           Retry           WTP
                           Pwr Mgmt        -
                           MoreData        WTP
                           Protected       WTP/AC
                           Order           AC
                   Duration:           WTP
                   Address 1:          AC
                   Address 2:          AC
                   Address 3:          AC
                   Sequence Ctrl:      WTP
                   Address 4:          AC
                   QoS Control:        AC
                   Frame Body:         AC
                   FCS:                WTP

       Figure 3: Population of the IEEE 802.11 MAC Header Fields for
                              Downlink Frames

   When 802.11 encryption/decryption is performed at the AC, the
   MoreFrag bit is populated at the AC.  The Pwr Mgmt bit is not
   applicable to downlink frames, and is set to 0.  Note that the Frame
   Check Sequence (FCS) field is not included in 802.11 frames exchanged
   between the WTP and the AC.  Upon sending data frames to the AC, the
   WTP is responsible for validating and stripping the FCS field.  Upon
   receiving data frames from the AC, the WTP is responsible for adding
   the FCS field, and populating the field as described in
   [IEEE.802-11.2007].

   Note that when the WTP tunnels data packets to the AC (and vice
   versa), the CAPWAP protocol does not guarantee in-order delivery.
   When the protocol being transported over IEEE 802.11 is IP, out-of-
   order delivery is not an issue as IP has no such requirements.
   However, implementers need to be aware of this protocol
   characteristic before deciding to use CAPWAP.

2.2.2.  Local MAC

   This section shows the division of labor between the WTP and the AC
   in a Local MAC architecture.  Figure 4 shows the separation of
   functionality among CAPWAP components.



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RFC 5416        CAPWAP Protocol Binding for IEEE 802.11       March 2009


        Function                               Location
            Distribution Service                      WTP/AC
            Integration Service                       WTP
            Beacon Generation                         WTP
            Probe Response Generation                 WTP
            Power Mgmt/Packet Buffering               WTP
            Fragmentation/Defragmentation             WTP
            Assoc/Disassoc/Reassoc                    WTP/AC

       IEEE 802.11 QoS
            Classifying                               WTP
            Scheduling                                WTP
            Queuing                                   WTP

       IEEE 802.11 RSN
            IEEE 802.1X/EAP                           AC
            RSNA Key Management                       AC
            IEEE 802.11 Encryption/Decryption         WTP

      Figure 4: Mapping of 802.11 Functions for Local AP Architecture

   In the Local MAC mode, the integration service exists on the WTP,
   while the distribution service MAY reside on either the WTP or the
   AC.  When it resides on the AC, station-generated frames are not
   forwarded to the AC in their native format, but encapsulated as 802.3
   frames.

   While the MAC is terminated on the WTP, it is necessary for the AC to
   be aware of mobility events within the WTPs.  Thus, the WTP MUST
   forward the IEEE 802.11 Association Request frames to the AC.  The AC
   MAY reply with a failed Association Response frame if it deems it
   necessary, and upon receipt of a failed Association Response frame
   from the AC, the WTP MUST send a Disassociation frame to the station.

   The IEEE 802.1X [IEEE.802-1X.2004], EAP, and IEEE RSNA Key Management
   [IEEE.802-11.2007] functions reside in the AC.  Therefore, the WTP
   MUST forward all IEEE 802.1X, EAP, and RSNA Key Management frames to
   the AC and forward the corresponding responses to the station.  This
   implies that the AAA client also resides on the AC.

   Note that in the following figure, the use of '( - )' indicates that
   processing of the frames is done on the WTP.









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RFC 5416        CAPWAP Protocol Binding for IEEE 802.11       March 2009


             Client                      WTP                         AC

                      Beacon
             <-----------------------------
                       Probe
             <---------------------------->
                        802.11 AUTH
             <-----------------------------
                                 802.11 Association
             <---------------------------( - )------------------------->
                                        Station Configuration Request
                                          [Add Station (Station MAC
                                          Address), IEEE 802.11 Add
                                          Station (WLAN ID), IEEE
                                          802.11 Session Key(Flag=A)]
                                            <-------------------------->
                    802.1X Authentication & 802.11 Key Exchange
             <--------------------------------------------------------->
                                        Station Configuration Request
                                          [Add Station(Station MAC
                                          Address), IEEE 802.11 Add
                                          Station (WLAN ID), IEEE 802.11
                                          Station session Key (Key=x),
                                          IEEE 802.11 Information
                                          Element(RSNIE(Pairwise
                                          Cipher=CCMP))]
                                            <-------------------------->
                               802.11 Action Frames
             <--------------------------------------------------------->
                     802.11 DATA
             <----------------------------->

                     Figure 5: Local MAC Message Flow

   Figure 5 provides an illustration of the division of labor in a Local
   MAC architecture.  In this example, a WLAN that is configured for
   IEEE 802.11 has been created using AES-CCMP for privacy.  The
   following process occurs:

   o  The WTP generates the IEEE 802.11 Beacon frames, using information
      provided to it through the Add WLAN (see Section 6.1) message
      element.

   o  The WTP processes a Probe Request frame and responds with a
      corresponding Probe Response frame.

   o  The WTP forwards the IEEE 802.11 Authentication and Association
      frames to the AC.



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   o  Once the association is complete, the AC transmits a Station
      Configuration Request message, which includes the Add Station
      message element, to the WTP (see Section 4.6.8 in [RFC5415]).  In
      the above example, the WLAN was configured for IEEE 802.1X, and
      therefore the IEEE 802.11 Station Session Key is included with the
      flag field's 'A' bit set.

   o  The WTP forwards all IEEE 802.1X and IEEE 802.11 key exchange
      messages to the AC for processing.

   o  The AC transmits another Station Configuration Request message,
      which includes:

      -  An Add Station message element, which MAY include a Virtual LAN
         (VLAN) [IEEE.802-1Q.2005] name, which when present is used by
         the WTP to identify the VLAN on which the user's data frames
         are to be bridged.

      -  An IEEE 802.11 Add Station message element, which includes the
         WLAN Identifier with which the station has associated.

      -  An IEEE 802.11 Station Session Key message element, which
         includes the pairwise encryption key.

      -  An IEEE 802.11 Information Element message element, which
         includes the RSNIE to the WTP, stating the security policy to
         enforce for the client (in this case AES-CCMP).

   o  The WTP forwards any IEEE 802.11 Management Action frames received
      to the AC.

   o  The WTP MAY locally bridge client data frames (and provide the
      necessary encryption and decryption services).  The WTP MAY also
      tunnel client data frames to the AC, using 802.3 frame tunnel mode
      or 802.11 frame tunnel mode.

2.3.  Roaming Behavior

   This section expands upon the examples provided in the previous
   section, and describes how the CAPWAP control protocol is used to
   provide secure roaming.

   Once a client has successfully associated with the network in a
   secure fashion, it is likely to attempt to roam to another WTP.
   Figure 6 shows an example of a currently associated station moving
   from its "Old WTP" to a "New WTP".  The figure is valid for multiple
   different security policies, including IEEE 802.1X and Wireless
   Protected Access (WPA) or Wireless Protected Access 2 (WPA2) [WPA].



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   In the event that key caching was employed, the 802.1X Authentication
   step would be eliminated.  Note that the example represents one where
   crypto services are provided by the WTP, so in a case where the AC
   provided this function the last Station Configuration Request would
   be different.

            Client              Old WTP            New WTP           AC

                          Association Request/Response
             <--------------------------------------( - )-------------->
                                        Station Configuration Request
                                          [Add Station (Station MAC
                                          Address), IEEE 802.11 Add
                                          Station (WLAN ID), IEEE
                                          802.11 Session Key(Flag=A)]
                                                      <---------------->
             802.1X Authentication (if no key cache entry exists)
             <--------------------------------------( - )-------------->
                           802.11 4-way Key Exchange
             <--------------------------------------( - )-------------->
                                Station Configuration Request
                                  [Delete Station]
                                    <---------------------------------->
                                        Station Configuration Request
                                          [Add Station(Station MAC
                                          Address), IEEE 802.11 Add
                                          Station (WLAN ID), IEEE 802.11
                                          Station session Key (Key=x),
                                          IEEE 802.11 Information
                                          Element(RSNIE(Pairwise
                                          Cipher=CCMP))]
                                                      <---------------->

                     Figure 6: Client Roaming Example

2.4.  Group Key Refresh

   Periodically, the Group Key (GTK) for the BSS needs to be updated.
   The AC uses an EAPOL-Key frame to update the group key for each STA
   in the BSS.  While the AC is updating the GTK, each Layer 2 (L2)
   broadcast frame transmitted to the BSS needs to be duplicated and
   transmitted using both the current GTK and the new GTK.  Once the GTK
   update process has completed, broadcast frames transmitted to the BSS
   will be encrypted using the new GTK.

   In the case of Split MAC, the AC needs to duplicate all broadcast
   packets and update the key index so that the packet is transmitted
   using both the current and new GTK to ensure that all STAs in the BSS



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   receive the broadcast frames.  In the case of Local MAC, the WTP
   needs to duplicate and transmit broadcast frames using the
   appropriate index to ensure that all STAs in the BSS continue to
   receive broadcast frames.

   The Group Key update procedure is shown in the following figure.  The
   AC will signal the update to the GTK using an IEEE 802.11
   Configuration Request message, including an IEEE 802.11 Update WLAN
   message element with the new GTK, its index, the Transmit Sequence
   Counter (TSC) for the Group Key and the Key Status set to 3 (begin
   GTK update).  The AC will then begin updating the GTK for each STA.
   During this time, the AC (for Split MAC) or WTP (for Local MAC) MUST
   duplicate broadcast packets and transmit them encrypted with both the
   current and new GTK.  When the AC has completed the GTK update to all
   STAs in the BSS, the AC MUST transmit an IEEE 802.11 Configuration
   Request message including an IEEE 802.11 Update WLAN message element
   containing the new GTK, its index, and the Key Status set to 4 (GTK
   update complete).

        Client           WTP                                          AC

                         IEEE 802.11 WLAN Configuration Request [Update
                           WLAN (GTK, GTK Index, GTK Start,
                           Group TSC) ]
                         <--------------------------------------------
                               802.1X EAPoL (GTK Message 1)
        <-------------( - )-------------------------------------------
                               802.1X EAPoL (GTK Message 2)
        -------------( - )------------------------------------------->
                         IEEE 802.11 WLAN Configuration Request [ Update
                           WLAN (GTK Index, GTK Complete) ]
                         <--------------------------------------------

                   Figure 7: Group Key Update Procedure

2.5.  BSSID to WLAN ID Mapping

   The CAPWAP protocol binding enables the WTP to assign BSSIDs upon
   creation of a WLAN (see Section 6.1).  While manufacturers are free
   to assign BSSIDs using any arbitrary mechanism, it is advised that
   where possible the BSSIDs are assigned as a contiguous block.

   When assigned as a block, implementations can still assign any of the
   available BSSIDs to any WLAN.  One possible method is for the WTP to
   assign the address using the following algorithm: base BSSID address
   + WLAN ID.





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   The WTP communicates the maximum number of BSSIDs that it supports
   during configuration via the IEEE 802.11 WTP WLAN Radio Configuration
   message element (see Section 6.23).

2.6.  CAPWAP Data Channel QoS Behavior

   The CAPWAP IEEE 802.11 binding specification provides procedures to
   allow for the WTP to enforce Quality of Service on IEEE 802.11 Data
   Frames and MAC Management messages.

2.6.1.  IEEE 802.11 Data Frames

   When the WLAN is created on the WTP, a default Quality of Service
   policy is established through the IEEE 802.11 WTP Quality of Service
   message element (see Section 6.22).  This default policy will cause
   the WTP to use the default QoS values for any station associated with
   the WLAN in question.  The AC MAY also override the policy for a
   given station by sending the IEEE 802.11 Update Station QoS message
   element (see Section 6.20), known as a station-specific QoS policy.

   Beyond the default, and per station QoS policy, the IEEE 802.11
   protocol also allows a station to request special QoS treatment for a
   specific flow through the Traffic Specification (TSPEC) Information
   Elements found in the IEEE 802.11-2007's QoS Action Frame.
   Alternatively, stations MAY also use the WiFi Alliance's WMM
   specification instead to request QoS treatment for a flow (see
   [WMM]).  This requires the WTP to observe the Status Code in the IEEE
   802.11-2007 and WMM QoS Action Add Traffic System (ADDTS) responses
   from the AC, and provide the services requested in the TSPEC
   Information Element.  Similarly, the WTP MUST observe the Reason Code
   Information Element in the IEEE 802.11-2007 and WMM QoS Action DELTS
   responses from the AC by removing the policy associated with the
   TSPEC.

   The IEEE 802.11 WTP Quality of Service message element's Tagging
   Policy field indicates how the packets are to be tagged, known as the
   Tagging Policy.  There are five bits defined, two of which are used
   to indicate the type of QoS to be used by the WTP.  The first is the
   'P' bit, which is set to inform the WTP it is to use the 802.1p QoS
   mechanism.  When set, the 'Q' bit is used to inform the WTP which
   802.1p priority values it is to use.

   The 'D' bit is set to inform the WTP it is to use the Differentiated
   Services Code Point (DSCP) QoS mechanism.  When set, the 'I' and 'O'
   bits are used to inform the WTP which values it is to use in the
   inner header, in the station's original packet, or the outer header,
   the latter of which is only valid when tunneling is enabled.




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   When an IEEE 802.11 Update Station QoS message element is received,
   while the specific 802.1p priority or DSCP values may change for a
   given station, known as the station specific policy, the original
   Tagging Policy (the use of the five bits) remains the same.

   The use of the DSCP and 802.1p QoS mechanisms are not mutually
   exclusive.  An AC MAY request that a WTP use none, one, or both types
   of QoS mechanisms at the same time.

2.6.1.1.  802.1p Support

   The IEEE 802.11 WTP Quality of Service and IEEE 802.11 Update Station
   QoS message elements include the "802.1p Tag" field, which is the
   802.1p priority value.  This value is used by the WTP by adding an
   802.1Q header (see [IEEE.802-1Q.2005]) with the priority field set
   according to the policy provided.  Note that this tagging is only
   valid for interfaces that support 802.1p.  The actual treatment does
   not change for either Split or Local MAC modes, or when tunneling is
   used.  The only exception is when tunneling is used, the 802.1Q
   header is added to the outer packet (tunneled) header.  The IEEE
   802.11 standard does not permit the station's packet to include an
   802.1Q header.  Instead, the QoS mechanisms defined in the IEEE
   802.11 standard are used by stations to mark a packet's priority.
   When the 'P' bit is set in the Tagging Policy, the 'Q' bit has the
   following behavior:

   Q=1:   The WTP marks the priority field in the 802.1Q header to
          either the default or the station-specific 802.1p policy.

   Q=0:   The WTP marks the priority field in the 802.1Q header to the
          value found in the User Priority field of the QoS Control
          field of the IEEE 802.11 header.  If the QoS Control field is
          not present in the IEEE 802.11 header, then the behavior
          described under 'Q=1' is used.

2.6.1.2.  DSCP Support

   The IEEE 802.11 WTP Quality of Service and IEEE 802.11 Update Station
   QoS message elements also provide a "DSCP Tag", which is used by the
   WTP when the 'D' bit is set to mark the DSCP field of both the IPv4
   and IPv6 headers (see [RFC2474]).  When DSCP is used, the WTP marks
   the inner packet (the original packet received by the station) when
   the 'I' bit is set.  Similarly, the WTP marks the outer packet
   (tunnel header's DSCP field) when the 'O' bit is set.

   When the 'D' bit is set, the treatment of the packet differs based on
   whether the WTP is tunneling the station's packets to the AC.
   Tunneling does not occur in a Local MAC mode when the AC has



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   communicated that tunneling is not required, as part of the IEEE
   802.11 Add WLAN message element, see Section 6.1.  In the case where
   tunneling is not used, the 'I' and 'O' bits have the following
   behaviors:

   O=1:   This option is invalid when tunneling is not enabled for
          station data frames.

   O=0:   This option is invalid when tunneling is not enabled for
          station data frames.

   I=1:   The WTP sets the DSCP field in the station's packet to either
          the default policy or the station-specific policy if one
          exists.

   I=0:   The WTP MUST NOT modify the DSCP field in the station's
          packet.

   For Split MAC mode, or Local MAC with tunneling enabled, the WTP
   needs to contend with both the inner packet (the station's original
   packet) as well as the tunnel header (added by the WTP).  In this
   mode of operation, the bits are treated as follows:

   O=1:   The WTP sets the DSCP field in the tunnel header to either the
          default policy or the station specific policy if one exists.

   O=0:   The WTP sets the DSCP field in the tunnel header to the value
          found in the inner packet's DSCP field.  If encryption
          services are provided by the AC (see Section 6.15), the packet
          is encrypted; therefore, the WTP cannot access the inner DSCP
          field, in which case it uses the behavior described when the
          'O' bit is set.  This occurs also if the inner packet is not
          IPv4 or IPv6, and thus does not have a DSCP field.

   I=1:   The WTP sets the DSCP field in the station's packet to either
          the default policy or the station-specific policy if one
          exists.  If encryption services are provided by the AC (see
          Section 6.15), the packet is encrypted; therefore, the WTP
          cannot access the inner DSCP field, in which case it uses the
          behavior described when the 'I' bit is not set.  This occurs
          also if the inner packet is not IPv4 or IPv6, and thus does
          not have a DSCP field.

   I=0:   The WTP MUST NOT modify the DSCP field in the station's
          packet.






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   The CAPWAP protocol supports the Explicit Congestion Notification
   (ECN) bits [RFC3168].  Additional details on ECN support can be found
   in [RFC5415].

2.6.2.  IEEE 802.11 MAC Management Messages

   It is recommended that IEEE 802.11 MAC Management frames be sent by
   both the AC and the WTP with appropriate Quality of Service values,
   listed below, to ensure that congestion in the network minimizes
   occurrences of packet loss.  Note that the QoS Mechanism specified in
   the Tagging Policy is used as specified by the AC in the IEEE 802.11
   WTP Quality of Service message element (see Section 6.22).  However,
   the station-specific policy is not used for IEEE 802.11 MAC
   Management frames.

   802.1p:   The precedence value of 7 (decimal) SHOULD be used for all
             IEEE 802.11 MAC management frames, except for Probe
             Requests, which SHOULD use 4.

   DSCP:     All IEEE 802.11 MAC management frames SHOULD use the CS6
             per- hop behavior (see [RFC2474]), while IEEE 802.11 Probe
             Requests should use the Low Drop Assured Forwarding per-hop
             behavior (see [RFC3246]).

2.7.  Run State Operation

   The Run state is the normal state of operation for the CAPWAP
   protocol in both the WTP and the AC.

   When the WTP receives a WLAN Configuration Request message (see
   Section 3.1), it MUST respond with a WLAN Configuration Response
   message (see Section 3.2), and it remains in the Run state.

   When the AC sends a WLAN Configuration Request message (see
   Section 3.1) or receives the corresponding WLAN Configuration
   Response message (see Section 3.2) from the WTP, it remains in the
   Run state.

3.  IEEE 802.11 Specific CAPWAP Control Messages

   This section defines CAPWAP Control messages that are specific to the
   IEEE 802.11 binding.  Two messages are defined: IEEE 802.11 WLAN
   Configuration Request and IEEE 802.11 WLAN Configuration Response.
   See Section 4.5 in [RFC5415] for CAPWAP Control message definitions
   and the derivation of the Message Type value from the IANA Enterprise
   number.





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   The valid message types for IEEE 802.11-specific control messages are
   listed below.  The IANA Enterprise number used with these messages is
   13277.

           CAPWAP Control Message                    Message Type
                                                        Value

           IEEE 802.11 WLAN Configuration Request      3398913
           IEEE 802.11 WLAN Configuration Response     3398914

3.1.  IEEE 802.11 WLAN Configuration Request

   The IEEE 802.11 WLAN Configuration Request is sent by the AC to the
   WTP in order to change services provided by the WTP.  This control
   message is used to either create, update, or delete a WLAN on the
   WTP.

   The IEEE 802.11 WLAN Configuration Request is sent as a result of
   either some manual administrative process (e.g., deleting a WLAN), or
   automatically to create a WLAN on a WTP.  When sent automatically to
   create a WLAN, this control message is sent after the CAPWAP
   Configuration Update Response message (see Section 8.5 in [RFC5415])
   has been received by the AC.

   Upon receiving this control message, the WTP will modify the
   necessary services and transmit an IEEE 802.11 WLAN Configuration
   Response.

   A WTP MAY provide service for more than one WLAN; therefore, every
   WLAN is identified through a numerical index.  For instance, a WTP
   that is capable of supporting up to 16 Service Set Identifiers
   (SSIDs), could accept up to 16 IEEE 802.11 WLAN Configuration Request
   messages that include the Add WLAN message element.

   Since the index is the primary identifier for a WLAN, an AC MAY
   attempt to ensure that the same WLAN is identified through the same
   index number on all of its WTPs.  An AC that does not follow this
   approach MUST find some other means of maintaining a WLAN-Identifier-
   to-SSID mapping table.

   The following message elements MAY be included in the IEEE 802.11
   WLAN Configuration Request message.  Only one message element MUST be
   present.

   o  IEEE 802.11 Add WLAN, see Section 6.1

   o  IEEE 802.11 Delete WLAN, see Section 6.4




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   o  IEEE 802.11 Update WLAN, see Section 6.21

   The following message element MAY be present.

   o  IEEE 802.11 Information Element, see Section 6.6

   o  Vendor-Specific Payload, see [RFC5415]

3.2.  IEEE 802.11 WLAN Configuration Response

   The IEEE 802.11 WLAN Configuration Response message is sent by the
   WTP to the AC.  It is used to acknowledge receipt of an IEEE 802.11
   WLAN Configuration Request message, and to indicate that the
   requested configuration was successfully applied or that an error
   related to the processing of the IEEE 802.11 WLAN Configuration
   Request message occurred on the WTP.

   The following message element MUST be included in the IEEE 802.11
   WLAN Configuration Response message.

   o  Result Code, see Section 4.6.34 in [RFC5415]

   The following message element MAY be included in the IEEE 802.11 WLAN
   Configuration Response message.

   o  IEEE 802.11 Assigned WTP BSSID, see Section 6.3

   o  Vendor-Specific Payload, see [RFC5415]

4.  CAPWAP Data Message Bindings

   This section describes the CAPWAP data message bindings to support
   transport of IEEE 802.11 frames.

   Payload encapsulation:  The CAPWAP protocol defines the CAPWAP data
      message, which is used to encapsulate a wireless payload.  For
      IEEE 802.11, the IEEE 802.11 header and payload are encapsulated
      (excluding the IEEE 802.11 FCS checksum).  The IEEE 802.11 FCS
      checksum is handled by the WTP.  This allows the WTP to validate
      an IEEE 802.11 frame prior to sending it to the AC.  Similarly,
      when an AC wishes to transmit a frame to a station, the WTP
      computes and adds the FCS checksum.

   Optional Wireless Specific Information:  This optional CAPWAP header
      field (see Section 4.3 in [RFC5415]) is only used with CAPWAP data
      messages, and it serves two purposes, depending upon the direction
      of the message.  For messages from the WTP to the AC, the field
      uses the format described in the "IEEE 802.11 Frame Info" field



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      (see below).  However, for messages sent by the AC to the WTP, the
      format used is described in the "Destination WLANs" field (also
      defined below).

      Note that in both cases, the two optional headers fit in the
      "Data" field of the Wireless Specific Information header.

   IEEE 802.11 Frame Info:  When an IEEE 802.11 frame is received from a
      station over the air, it is encapsulated and this field is used to
      include radio and PHY-specific information associated with the
      frame.

      The IEEE 802.11 Frame Info field has the following format:

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     RSSI      |     SNR       |           Data Rate           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      RSSI:   Received Signal Strength Indication (RSSI) is a signed,
         8-bit value.  It is the received signal strength indication, in
         dBm.

      SNR:   SNR is a signed, 8-bit value.  It is the signal-to-noise
         ratio of the received IEEE 802.11 frame, in dB.

      Data Rate:   The data rate field is a 16-bit unsigned value.  The
         data rate field is a 16-bit unsigned value expressing the data
         rate of the packets received by the WTP in units of 0.1 Mbps.
         For instance, a packet received at 5.5 Mbps would be set to 55,
         while 11 Mbps would be set to 110.

   Destination WLANs:  The Destination WLANs field is used to specify
      the target WLANs for a given frame, and is only used with
      broadcast and multicast frames.  This field allows the AC to
      transmit a single broadcast or multicast frame to the WTP and
      allows the WTP to perform the necessary frame replication.  The
      field uses the following format:

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |        WLAN ID bitmap         |            Reserved           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+






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      WLAN ID bitmap:   This bit field indicates the WLAN ID (see
         Section 6.1) on which the WTP will transmit the included frame.
         For instance, if a multicast packet is to be transmitted on
         WLANs 1 and 3, the bits for WLAN 1 and 3 of this field would be
         enabled.  WLAN 1 is represented by bit 15 in the figure above,
         or the least significant bit, while WLAN 16 would be
         represented by bit zero (0), or the most significant bit, in
         the figure.  This field is to be set to all zeroes for unicast
         packets and is unused if the WTP is not providing IEEE 802.11
         encryption.

      Reserved:   All implementations complying with this protocol MUST
         set to zero any bits that are reserved in the version of the
         protocol supported by that implementation.  Receivers MUST
         ignore all bits not defined for the version of the protocol
         they support.

5.  CAPWAP Control Message Bindings

   This section describes the IEEE 802.11-specific message elements
   included in CAPWAP Control Messages.

5.1.  Discovery Request Message

   The following IEEE 802.11-specific message element MUST be included
   in the CAPWAP Discovery Request Message.

   o  IEEE 802.11 WTP Radio Information, see Section 6.25.  An IEEE
      802.11 WTP Radio Information message element MUST be present for
      every radio in the WTP.

5.2.  Discovery Response Message

   The following IEEE 802.11-specific message element MUST be included
   in the CAPWAP Discovery Response Message.

   o  IEEE 802.11 WTP Radio Information, see Section 6.25.  An IEEE
      802.11 WTP Radio Information message element MUST be present for
      every radio in the WTP.

5.3.  Primary Discovery Request Message

   The following IEEE 802.11 specific message element MUST be included
   in the CAPWAP Primary Discovery Request message.

   o  IEEE 802.11 WTP Radio Information, see Section 6.25.  An IEEE
      802.11 WTP Radio Information message element MUST be present for
      every radio in the WTP.



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5.4.  Primary Discovery Response Message

   The following IEEE 802.11-specific message element MUST be included
   in the CAPWAP Primary Discovery Response message.

   o  IEEE 802.11 WTP Radio Information, see Section 6.25.  An IEEE
      802.11 WTP Radio Information message element MUST be present for
      every radio in the WTP.

5.5.  Join Request Message

   The following IEEE 802.11-specific message element MUST be included
   in the CAPWAP Join Request message.

   o  IEEE 802.11 WTP Radio Information, see Section 6.25.  An IEEE
      802.11 WTP Radio Information message element MUST be present for
      every radio in the WTP.

5.6.  Join Response Message

   The following IEEE 802.11-specific message element MUST be included
   in the CAPWAP Join Response message.

   o  IEEE 802.11 WTP Radio Information, see Section 6.25.  An IEEE
      802.11 WTP Radio Information message element MUST be present for
      every radio in the WTP.

5.7.  Configuration Status Request Message

   The following IEEE 802.11-specific message elements MAY be included
   in the CAPWAP Configuration Status Request message.  More than one of
   each message element listed MAY be included.

   o  IEEE 802.11 Antenna, see Section 6.2

   o  IEEE 802.11 Direct Sequence Control, see Section 6.5

   o  IEEE 802.11 MAC Operation, see Section 6.7

   o  IEEE 802.11 Multi-Domain Capability, see Section 6.9

   o  IEEE 802.11 Orthogonal Frequency Division Multiplexing (OFDM)
      Control, see Section 6.10

   o  IEEE 802.11 Supported Rates, see Section 6.17

   o  IEEE 802.11 Tx Power, see Section 6.18




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   o  IEEE 802.11 TX Power Level, see Section 6.19

   o  IEEE 802.11 WTP Radio Configuration, see Section 6.23

   o  IEEE 802.11 WTP Radio Information, see Section 6.25.  An IEEE
      802.11 WTP Radio Information message element MUST be present for
      every radio in the WTP.

5.8.  Configuration Status Response Message

   The following IEEE 802.11 specific message elements MAY be included
   in the CAPWAP Configuration Status Response Message.  More than one
   of each message element listed MAY be included.

   o  IEEE 802.11 Antenna, see Section 6.2

   o  IEEE 802.11 Direct Sequence Control, see Section 6.5

   o  IEEE 802.11 MAC Operation, see Section 6.7

   o  IEEE 802.11 Multi-Domain Capability, see Section 6.9

   o  IEEE 802.11 OFDM Control, see Section 6.10

   o  IEEE 802.11 Rate Set, see Section 6.11

   o  IEEE 802.11 Supported Rates, see Section 6.17

   o  IEEE 802.11 Tx Power, see Section 6.18

   o  IEEE 802.11 WTP Quality of Service, see Section 6.22

   o  IEEE 802.11 WTP Radio Configuration, see Section 6.23

5.9.  Configuration Update Request Message

   The following IEEE 802.11-specific message elements MAY be included
   in the CAPWAP Configuration Update Request message.  More than one of
   each message element listed MAY be included.

   o  IEEE 802.11 Antenna, see Section 6.2

   o  IEEE 802.11 Direct Sequence Control, see Section 6.5

   o  IEEE 802.11 MAC Operation, see Section 6.7

   o  IEEE 802.11 Multi-Domain Capability, see Section 6.9




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   o  IEEE 802.11 OFDM Control, see Section 6.10

   o  IEEE 802.11 Rate Set, see Section 6.11

   o  IEEE 802.11 RSNA Error Report from Station, see Section 6.12

   o  IEEE 802.11 Tx Power, see Section 6.18

   o  IEEE 802.11 WTP Quality of Service, see Section 6.22

   o  IEEE 802.11 WTP Radio Configuration, see Section 6.23

5.10.  Station Configuration Request

   The following IEEE 802.11-specific message elements MAY be included
   in the CAPWAP Station Configuration Request message.  More than one
   of each message element listed MAY be included.

   o  IEEE 802.11 Station, see Section 6.13

   o  IEEE 802.11 Station Session Key, see Section 6.15

   o  IEEE 802.11 Station QoS Profile, see Section 6.14

   o  IEEE 802.11 Update Station Qos, see Section 6.20

5.11.  Change State Event Request

   The following IEEE 802.11-specific message element MAY be included in
   the CAPWAP Station Configuration Request message.

   o  IEEE 802.11 WTP Radio Fail Alarm Indication, see Section 6.24

5.12.  WTP Event Request

   The following IEEE 802.11-specific message elements MAY be included
   in the CAPWAP WTP Event Request message.  More than one of each
   message element listed MAY be included.

   o  IEEE 802.11 MIC Countermeasures, see Section 6.8

   o  IEEE 802.11 RSNA Error Report from Station, see Section 6.12

   o  IEEE 802.11 Statistics, see Section 6.16







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6.  IEEE 802.11 Message Element Definitions

   The following IEEE 802.11-specific message elements are defined in
   this section.

   IEEE 802.11 Message Element                     Type Value

   IEEE 802.11 Add WLAN                               1024
   IEEE 802.11 Antenna                                1025
   IEEE 802.11 Assigned WTP BSSID                     1026
   IEEE 802.11 Delete WLAN                            1027
   IEEE 802.11 Direct Sequence Control                1028
   IEEE 802.11 Information Element                    1029
   IEEE 802.11 MAC Operation                          1030
   IEEE 802.11 MIC Countermeasures                    1031
   IEEE 802.11 Multi-Domain Capability                1032
   IEEE 802.11 OFDM Control                           1033
   IEEE 802.11 Rate Set                               1034
   IEEE 802.11 RSNA Error Report From Station         1035
   IEEE 802.11 Station                                1036
   IEEE 802.11 Station QoS Profile                    1037
   IEEE 802.11 Station Session Key                    1038
   IEEE 802.11 Statistics                             1039
   IEEE 802.11 Supported Rates                        1040
   IEEE 802.11 Tx Power                               1041
   IEEE 802.11 Tx Power Level                         1042
   IEEE 802.11 Update Station QoS                     1043
   IEEE 802.11 Update WLAN                            1044
   IEEE 802.11 WTP Quality of Service                 1045
   IEEE 802.11 WTP Radio Configuration                1046
   IEEE 802.11 WTP Radio Fail Alarm Indication        1047
   IEEE 802.11 WTP Radio Information                  1048

              Figure 8: IEEE 802.11 Binding Message Elements

6.1.  IEEE 802.11 Add WLAN

   The IEEE 802.11 Add WLAN message element is used by the AC to define
   a WLAN on the WTP.  The inclusion of this message element MUST also
   include IEEE 802.11 Information Element message elements, containing
   the following IEEE 802.11 IEs:

   Power Constraint information element

   EDCA Parameter Set information element

   QoS Capability information element




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   WPA information element  [WPA]

   RSN information element

   WMM information element  [WMM]

   These IEEE 802.11 Information Elements are stored by the WTP and
   included in any Probe Responses and Beacons generated, as specified
   in the IEEE 802.11 standard [IEEE.802-11.2007].  If present, the RSN
   Information Element is sent with the IEEE 802.11 Add WLAN message
   element to instruct the WTP on the usage of the Key field.

   If cryptographic services are provided at the WTP, the WTP MUST
   observe the algorithm dictated in the Group Cipher Suite field of the
   RSN Information Element sent by the AC.  The RSN Information Element
   is used to communicate any supported algorithm, including WEP,
   Temporal Key Integrity Protocol (TKIP) and AES-CCMP.  In the case of
   static WEP keys, the RSN Information Element is still used to
   indicate the cryptographic algorithm even though no key exchange
   occurred.

   An AC MAY include additional Information Elements as desired.  The
   message element uses the following format:

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |    WLAN ID    |          Capability           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   Key Index   |   Key Status  |           Key Length          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                             Key...                            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                           Group TSC                           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |           Group TSC           |      QoS      |   Auth Type   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   MAC Mode    |  Tunnel Mode  | Suppress SSID |    SSID ...
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1024 for IEEE 802.11 Add WLAN

   Length:   >= 20

   Radio ID:   An 8-bit value representing the radio, whose value is
      between one (1) and 31.





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   WLAN ID:   An 8-bit value specifying the WLAN Identifier.  The value
      MUST be between one (1) and 16.

   Capability:   A 16-bit value containing the Capability information
      field to be advertised by the WTP in the Probe Request and Beacon
      frames.  Each bit of the Capability field represents a different
      WTP capability, which are described in detail in
      [IEEE.802-11.2007].  The format of the field is:

        0                   1
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |E|I|C|F|P|S|B|A|M|Q|T|D|V|O|K|L|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      E (ESS):   The AC MUST set the Extended Service Set (ESS) subfield
        to 1.

      I (IBSS):   The AC MUST set the Independent Basic Service Set
        (IBSS) subfield to 0.

      C (CF-Pollable):   The AC sets the Contention Free Pollable (CF-
        Pollable) subfield based on the table found in
        [IEEE.802-11.2007].

      F (CF-Poll Request):   The AC sets the CF-Poll Request subfield
        based on the table found in [IEEE.802-11.2007].

      P (Privacy):   The AC sets the Privacy subfield based on the
        confidentiality requirements of the WLAN, as defined in
        [IEEE.802-11.2007].

      S (Short Preamble):   The AC sets the Short Preamble subfield
        based on whether the use of short preambles is permitted on the
        WLAN, as defined in [IEEE.802-11.2007].

      B (PBCC):   The AC sets the Packet Binary Convolutional Code
        (PBCC) modulation option subfield based on whether the use of
        PBCC is permitted on the WLAN, as defined in [IEEE.802-11.2007].

      A (Channel Agility):   The AC sets the Channel Agility subfield
        based on whether the WTP is capable of supporting the High Rate
        Direct Sequence Spread Spectrum (HR/DSSS), as defined in
        [IEEE.802-11.2007].







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      M (Spectrum Management):   The AC sets the Spectrum Management
        subfield according to the value of the
        dot11SpectrumManagementRequired MIB variable, as defined in
        [IEEE.802-11.2007].

      Q (QoS):   The AC sets the Quality of Service (QoS) subfield based
        on the table found in [IEEE.802-11.2007].

      T (Short Slot Time):   The AC sets the Short Slot Time subfield
        according to the value of the WTP's currently used slot time
        value, as defined in [IEEE.802-11.2007].

      D (APSD):   The AC sets the Automatic Power Save Delivery (APSD)
        subfield according to the value of the
        dot11APSDOptionImplemented Management Information Base (MIB)
        variable, as defined in [IEEE.802-11.2007].

      V (Reserved):   The AC sets the Reserved subfield to zero, as
        defined in [IEEE.802-11.2007].

      O (DSSS-OFDM):   The AC sets the DSSS-OFDM subfield to indicate
        the use of Direct Sequence Spread Spectrum with Orthogonal
        Frequency Division Multiplexing (DSSS-OFDM), as defined in
        [IEEE.802-11.2007].

      K (Delayed Block ACK):   The AC sets the Delayed Block ACK
        subfield according to the value of the
        dot11DelayedBlockAckOptionImplemented MIB variable, as defined
        in [IEEE.802-11.2007].

      L (Immediate Block ACK):   The AC sets the Delayed Block ACK
        subfield according to the value of the
        dot11ImmediateBlockAckOptionImplemented MIB variable, as defined
        in [IEEE.802-11.2007].

   Key-Index:   The Key Index associated with the key.

   Key Status:   A 1-byte value that specifies the state and usage of
      the key that has been included.  Note this field is ignored if the
      Key Length field is set to zero (0).  The following values
      describe the key usage and its status:

      0 -  A value of zero, with the inclusion of the RSN Information
           Element means that the WLAN uses per-station encryption keys,
           and therefore the key in the 'Key' field is only used for
           multicast traffic.





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      1 -  When set to one, the WLAN employs a shared Wired Equivalent
           Privacy (WEP) key, also known as a static WEP key, and uses
           the encryption key for both unicast and multicast traffic for
           all stations.

      2 -  The value of 2 indicates that the AC will begin rekeying the
           GTK with the STA's in the BSS.  It is only valid when IEEE
           802.11 is enabled as the security policy for the BSS.

      3 -  The value of 3 indicates that the AC has completed rekeying
           the GTK and broadcast packets no longer need to be duplicated
           and transmitted with both GTK's.

   Key Length:   A 16-bit value representing the length of the Key
      field.

   Key:   A Session Key, whose length is known via the Key Length field,
      used to provide data privacy.  For encryption schemes that employ
      a separate encryption key for unicast and multicast traffic, the
      key included here only applies to multicast frames, and the cipher
      suite is specified in an accompanied RSN Information Element.  In
      these scenarios, the key and cipher information is communicated
      via the Add Station message element, see Section 4.6.8 in
      [RFC5415] and the IEEE 802.11 Station Session Key message element,
      see Section 6.15.  When used with WEP, the key field includes the
      broadcast key.  When used with CCMP, the Key field includes the
      128-bit Group Temporal Key.  When used with TKIP, the Key field
      includes the 256-bit Group Temporal Key (which consists of a 128-
      bit key used as input for TKIP key mixing, and two 64-bit keys
      used for Michael).

   Group TSC:   A 48-bit value containing the Transmit Sequence Counter
      (TSC) for the updated group key.  The WTP will set the TSC for
      broadcast/multicast frames to this value for the updated group
      key.

   QoS:   An 8-bit value specifying the default QoS policy for the WTP
      to apply to network traffic received for a non-WMM enabled STA.

      The following enumerated values are supported:

      0 -  Best Effort

      1 -  Video







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      2 -  Voice

      3 -  Background

   Auth Type:   An 8-bit value specifying the supported authentication
      type.

      The following enumerated values are supported:

      0 -  Open System

      1 -  WEP Shared Key

   MAC Mode:   This field specifies whether the WTP should support the
      WLAN in Local or Split MAC mode.  Note that the AC MUST NOT
      request a mode of operation that was not advertised by the WTP
      during the discovery process (see Section 4.6.43 in [RFC5415]).
      The following enumerated values are supported:

      0 - Local MAC:   Service for the WLAN is to be provided in Local
         MAC mode.

      1 - Split MAC:   Service for the WLAN is to be provided in Split
         MAC mode.

   Tunnel Mode:   This field specifies the frame tunneling type to be
      used for 802.11 data frames from all stations associated with the
      WLAN.  The AC MUST NOT request a mode of operation that was not
      advertised by the WTP during the discovery process (see Section
      4.6.42 in [RFC5415]).  All IEEE 802.11 management frames MUST be
      tunneled using 802.11 Tunnel mode.  The following enumerated
      values are supported:

      0 - Local Bridging:   All user traffic is to be locally bridged.

      1 - 802.3 Tunnel:   All user traffic is to be tunneled to the AC
         in 802.3 format (see Section 4.4.2 in [RFC5415]).  Note that
         this option MUST NOT be selected with Split MAC mode.

      2 - 802.11 Tunnel:   All user traffic is to be tunneled to the AC
         in 802.11 format.

   Suppress SSID:   A boolean indicating whether the SSID is to be
      advertised by the WTP.  A value of zero suppresses the SSID in the
      802.11 Beacon and Probe Response frames, while a value of one will
      cause the WTP to populate the field.





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   SSID:   The SSID attribute is the service set identifier that will be
      advertised by the WTP for this WLAN.  The SSID field contains any
      ASCII character and MUST NOT exceed 32 octets in length, as
      defined in [IEEE.802-11.2007].

6.2.  IEEE 802.11 Antenna

   The IEEE 802.11 Antenna message element is communicated by the WTP to
   the AC to provide information on the antennas available.  The AC MAY
   use this element to reconfigure the WTP's antennas.  The message
   element contains the following fields:

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |   Diversity   |    Combiner   |  Antenna Cnt  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       | Antenna Selection...
       +-+-+-+-+-+-+-+-+

   Type:   1025 for IEEE 802.11 Antenna

   Length:   >= 5

   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.

   Diversity:   An 8-bit value specifying whether the antenna is to
      provide receiver diversity.  The value of this field is the same
      as the IEEE 802.11 dot11DiversitySelectionRx MIB element, see
      [IEEE.802-11.2007].  The following enumerated values are
      supported:

      0 -  Disabled

      1 -  Enabled (may only be true if the antenna can be used as a
           receiving antenna)

   Combiner:   An 8-bit value specifying the combiner selection.  The
      following enumerated values are supported:

      1 -  Sectorized (Left)

      2 -  Sectorized (Right)







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      3 -  Omni

      4 -  Multiple Input/Multiple Output (MIMO)

   Antenna Count:   An 8-bit value specifying the number of Antenna
      Selection fields.  This value SHOULD be the same as the one found
      in the IEEE 802.11 dot11CurrentTxAntenna MIB element (see
      [IEEE.802-11.2007]).

   Antenna Selection:   One 8-bit antenna configuration value per
      antenna in the WTP, containing up to 255 antennas.  The following
      enumerated values are supported:

      1 -  Internal Antenna

      2 -  External Antenna

6.3.  IEEE 802.11 Assigned WTP BSSID

   The IEEE 802.11 Assigned WTP BSSID is only included by the WTP when
   the IEEE 802.11 WLAN Configuration Request included the IEEE 802.11
   Add WLAN message element.  The BSSID value field of this message
   element contains the BSSID that has been assigned by the WTP,
   enabling the WTP to perform its own BSSID assignment.

   The WTP is free to assign the BSSIDs the way it sees fit, but it is
   highly recommended that the WTP assign the BSSID using the following
   algorithm: BSSID = {base BSSID} + WLAN ID.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |    WLAN ID    |           BSSID
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                             BSSID                             |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1026 for IEEE 802.11 Assigned WTP BSSID

   Length:   8

   Radio ID:   An 8-bit value representing the radio, whose value is
      between one (1) and 31.

   WLAN ID:   An 8-bit value specifying the WLAN Identifier.  The value
      MUST be between one (1) and 16.





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   BSSID:   The BSSID assigned by the WTP for the WLAN created as a
      result of receiving an IEEE 802.11 Add WLAN.

6.4.  IEEE 802.11 Delete WLAN

   The IEEE 802.11 Delete WLAN message element is used to inform the WTP
   that a previously created WLAN is to be deleted, and contains the
   following fields:

      0                   1
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Radio ID   |    WLAN ID    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1027 for IEEE 802.11 Delete WLAN

   Length:   2

   Radio ID:   An 8-bit value representing the radio, whose value is
      between one (1) and 31.

   WLAN ID:   An 8-bit value specifying the WLAN Identifier.  The value
      MUST be between one (1) and 16.

6.5.  IEEE 802.11 Direct Sequence Control

   The IEEE 802.11 Direct Sequence Control message element is a bi-
   directional element.  When sent by the WTP, it contains the current
   state.  When sent by the AC, the WTP MUST adhere to the values
   provided.  This element is only used for IEEE 802.11b radios.  The
   message element has the following fields.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |    Reserved   | Current Chan  |  Current CCA  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                    Energy Detect Threshold                    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1028 for IEEE 802.11 Direct Sequence Control

   Length:   8







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   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.

   Reserved:   All implementations complying with this protocol MUST set
      to zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.

   Current Channel:   This attribute contains the current operating
      frequency channel of the Direct Sequence Spread Spectrum (DSSS)
      PHY.  This value comes from the IEEE 802.11 dot11CurrentChannel
      MIB element (see [IEEE.802-11.2007]).

   Current CCA:   The current Clear Channel Assessment (CCA) method in
      operation, whose value can be found in the IEEE 802.11
      dot11CCAModeSupported MIB element (see [IEEE.802-11.2007]).  Valid
      values are:

         1 - energy detect only (edonly)

         2 - carrier sense only (csonly)

         4 - carrier sense and energy detect (edandcs)

         8 - carrier sense with timer (cswithtimer)

        16 - high rate carrier sense and energy detect (hrcsanded)

   Energy Detect Threshold:   The current Energy Detect Threshold being
      used by the DSSS PHY.  The value can be found in the IEEE 802.11
      dot11EDThreshold MIB element (see [IEEE.802-11.2007]).

6.6.  IEEE 802.11 Information Element

   The IEEE 802.11 Information Element is used to communicate any IE
   defined in the IEEE 802.11 protocol.  The data field contains the raw
   IE as it would be included within an IEEE 802.11 MAC management
   message.

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |    WLAN ID    |B|P| Reserved  |Info Element...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+







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   Type:   1029 for IEEE 802.11 Information Element

   Length:   >= 4

   Radio ID:   An 8-bit value representing the radio, whose value is
      between one (1) and 31.

   WLAN ID:   An 8-bit value specifying the WLAN Identifier.  The value
      MUST be between one (1) and 16.

   B:   When set, the WTP is to include the Information Element in IEEE
      802.11 Beacons associated with the WLAN.

   P:   When set, the WTP is to include the Information Element in Probe
      Responses associated with the WLAN.

   Reserved:   All implementations complying with this protocol MUST set
      to zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.

   Info Element:   The IEEE 802.11 Information Element, which includes
      the type, length, and value field.

6.7.  IEEE 802.11 MAC Operation

   The IEEE 802.11 MAC Operation message element is sent by the AC to
   set the IEEE 802.11 MAC parameters on the WTP, and contains the
   following fields.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |    Reserved   |         RTS Threshold         |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Short Retry  |  Long Retry   |    Fragmentation Threshold    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Tx MSDU Lifetime                        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Rx MSDU Lifetime                        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1030 for IEEE 802.11 MAC Operation

   Length:   16






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   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.

   Reserved:   All implementations complying with this protocol MUST set
      to zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.

   RTS Threshold:   This attribute indicates the number of octets in an
      MAC Protocol Data Unit (MPDU), below which a Request To Send/Clear
      To Send (RTS/CTS) handshake MUST NOT be performed.  An RTS/CTS
      handshake MUST be performed at the beginning of any frame exchange
      sequence where the MPDU is of type Data or Management, the MPDU
      has an individual address in the Address1 field, and the length of
      the MPDU is greater than this threshold.  Setting this attribute
      to be larger than the maximum MSDU size MUST have the effect of
      turning off the RTS/CTS handshake for frames of Data or Management
      type transmitted by this STA.  Setting this attribute to zero MUST
      have the effect of turning on the RTS/CTS handshake for all frames
      of Data or Management type transmitted by this STA.  The default
      value of this attribute MUST be 2347.  The value of this field
      comes from the IEEE 802.11 dot11RTSThreshold MIB element, (see
      [IEEE.802-11.2007]).

   Short Retry:   This attribute indicates the maximum number of
      transmission attempts of a frame, the length of which is less than
      or equal to RTSThreshold, that MUST be made before a failure
      condition is indicated.  The default value of this attribute MUST
      be 7.  The value of this field comes from the IEEE 802.11
      dot11ShortRetryLimit MIB element, (see [IEEE.802-11.2007]).

   Long Retry:   This attribute indicates the maximum number of
      transmission attempts of a frame, the length of which is greater
      than dot11RTSThreshold, that MUST be made before a failure
      condition is indicated.  The default value of this attribute MUST
      be 4.  The value of this field comes from the IEEE 802.11
      dot11LongRetryLimit MIB element, (see [IEEE.802-11.2007]).

   Fragmentation Threshold:   This attribute specifies the current
      maximum size, in octets, of the MPDU that MAY be delivered to the
      PHY.  A MAC Service Data Unit (MSDU) MUST be broken into fragments
      if its size exceeds the value of this attribute after adding MAC
      headers and trailers.  An MSDU or MAC Management Protocol Data
      Unit (MMPDU) MUST be fragmented when the resulting frame has an
      individual address in the Address1 field, and the length of the
      frame is larger than this threshold.  The default value for this
      attribute MUST be the lesser of 2346 or the aMPDUMaxLength of the
      attached PHY and MUST never exceed the lesser of 2346 or the



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      aMPDUMaxLength of the attached PHY.  The value of this attribute
      MUST never be less than 256.  The value of this field comes from
      the IEEE 802.11 dot11FragmentationThreshold MIB element, (see
      [IEEE.802-11.2007]).

   Tx MSDU Lifetime:   This attribute specifies the elapsed time in Time
      Units (TUs), after the initial transmission of an MSDU, after
      which further attempts to transmit the MSDU MUST be terminated.
      The default value of this attribute MUST be 512.  The value of
      this field comes from the IEEE 802.11 dot11MaxTransmitMSDULifetime
      MIB element, (see [IEEE.802-11.2007]).

   Rx MSDU Lifetime:   This attribute specifies the elapsed time in TU,
      after the initial reception of a fragmented MMPDU or MSDU, after
      which further attempts to reassemble the MMPDU or MSDU MUST be
      terminated.  The default value MUST be 512.  The value of this
      field comes from the IEEE 802.11 dot11MaxReceiveLifetime MIB
      element, (see [IEEE.802-11.2007]).

6.8.  IEEE 802.11 MIC Countermeasures

   The IEEE 802.11 MIC Countermeasures message element is sent by the
   WTP to the AC to indicate the occurrence of a MIC failure.  For more
   information on MIC failure events, see the
   dot11RSNATKIPCounterMeasuresInvoked MIB element definition in
   [IEEE.802-11.2007].

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |    WLAN ID    |          MAC Address          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          MAC Address                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1031 for IEEE 802.11 MIC Countermeasures

   Length:   8

   Radio ID:   The Radio Identifier, whose value is between one (1) and
      31, typically refers to some interface index on the WTP.

   WLAN ID:   This 8-bit unsigned integer includes the WLAN Identifier,
      on which the MIC failure occurred.  The value MUST be between one
      (1) and 16.






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   MAC Address:   The MAC Address of the station that caused the MIC
      failure.

6.9.  IEEE 802.11 Multi-Domain Capability

   The IEEE 802.11 Multi-Domain Capability message element is used by
   the AC to inform the WTP of regulatory limits.  The AC will transmit
   one message element per frequency band to indicate the regulatory
   constraints in that domain.  The message element contains the
   following fields.

         0                   1                   2                   3
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |    Reserved   |        First Channel #        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |       Number of Channels      |       Max Tx Power Level      |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1032 for IEEE 802.11 Multi-Domain Capability

   Length:   8

   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.

   Reserved:   All implementations complying with this protocol MUST set
      to zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.

   First Channel #:   This attribute indicates the value of the lowest
      channel number in the sub-band for the associated domain country
      string.  The value of this field comes from the IEEE 802.11
      dot11FirstChannelNumber MIB element (see [IEEE.802-11.2007]).

   Number of Channels:   This attribute indicates the value of the total
      number of channels allowed in the sub-band for the associated
      domain country string (see Section 6.23).  The value of this field
      comes from the IEEE 802.11 dot11NumberofChannels MIB element (see
      [IEEE.802-11.2007]).

   Max Tx Power Level:   This attribute indicates the maximum transmit
      power, in dBm, allowed in the sub-band for the associated domain
      country string (see Section 6.23).  The value of this field comes
      from the IEEE 802.11 dot11MaximumTransmitPowerLevel MIB element
      (see [IEEE.802-11.2007]).




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6.10.  IEEE 802.11 OFDM Control

   The IEEE 802.11 Orthogonal Frequency Division Multiplexing (OFDM)
   Control message element is a bi-directional element.  When sent by
   the WTP, it contains the current state.  When sent by the AC, the WTP
   MUST adhere to the received values.  This message element is only
   used for 802.11a radios and contains the following fields:

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |    Reserved   | Current Chan  |  Band Support |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                         TI Threshold                          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1033 for IEEE 802.11 OFDM Control

   Length:   8

   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.

   Reserved:   All implementations complying with this protocol MUST set
      to zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.

   Current Channel:   This attribute contains the current operating
      frequency channel of the OFDM PHY.  The value of this field comes
      from the IEEE 802.11 dot11CurrentFrequency MIB element (see
      [IEEE.802-11.2007]).

   Band Supported:   The capability of the OFDM PHY implementation to
      operate in the three Unlicensed National Information
      Infrastructure (U-NII) bands.  The value of this field comes from
      the IEEE 802.11 dot11FrequencyBandsSupported MIB element (see
      [IEEE.802-11.2007]), coded as a bit field, whose values are:

      Bit 0 -  capable of operating in the 5.15-5.25 GHz band

      Bit 1 -  capable of operating in the 5.25-5.35 GHz band

      Bit 2 -  capable of operating in the 5.725-5.825 GHz band







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      Bit 3 -  capable of operating in the 5.47-5.725 GHz band

      Bit 4 -  capable of operating in the lower Japanese 5.25 GHz band

      Bit 5 -  capable of operating in the 5.03-5.091 GHz band

      Bit 6 -  capable of operating in the 4.94-4.99 GHz band

      For example, for an implementation capable of operating in the
      5.15-5.35 GHz bands, this attribute would take the value 3.

   TI Threshold:   The threshold being used to detect a busy medium
      (frequency).  CCA MUST report a busy medium upon detecting the
      RSSI above this threshold.  The value of this field comes from the
      IEEE 802.11 dot11TIThreshold MIB element (see [IEEE.802-11.2007]).

6.11.  IEEE 802.11 Rate Set

   The rate set message element value is sent by the AC and contains the
   supported operational rates.  It contains the following fields.

         0                   1                   2                   3
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |                 Rate Set...
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1034 for IEEE 802.11 Rate Set

   Length:   >= 3

   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.

   Rate Set:   The AC generates the Rate Set that the WTP is to include
      in its Beacon and Probe messages.  The length of this field is
      between 2 and 8 bytes.  The value of this field comes from the
      IEEE 802.11 dot11OperationalRateSet MIB element (see
      [IEEE.802-11.2007]).

6.12.  IEEE 802.11 RSNA Error Report From Station

   The IEEE 802.11 RSN Error Report From Station message element is used
   by a WTP to send RSN error reports to the AC.  The WTP does not need
   to transmit any reports that do not include any failures.  The fields
   from this message element come from the IEEE 802.11
   Dot11RSNAStatsEntry table, see [IEEE.802-11.2007].




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      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                       Client MAC Address                      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      Client MAC Address       |             BSSID             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             BSSID                             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |    WLAN ID    |           Reserved            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        TKIP ICV Errors                        |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                    TKIP Local MIC Failures                    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                   TKIP Remote MIC Failures                    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          CCMP Replays                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        CCMP Decrypt Errors                    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          TKIP Replays                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Type:   1035 for IEEE 802.11 RSNA Error Report From Station

   Length:   40

   Client MAC Address:   The Client MAC Address of the station.

   BSSID:   The BSSID on which the failures are being reported.

   Radio ID:   The Radio Identifier, whose value is between one (1) and
      31, typically refers to some interface index on the WTP.

   WLAN ID:   The WLAN ID on which the RSNA failures are being reported.
      The value MUST be between one (1) and 16.

   Reserved:   All implementations complying with this protocol MUST set
      to zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.








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   TKIP ICV Errors:   A 32-bit value representing the number of Temporal
      Key Integrity Protocol (TKIP) (as defined in [IEEE.802-11.2007])
      ICV errors encountered when decrypting packets from the station.
      The value of this field comes from the IEEE 802.11
      dot11RSNAStatsTKIPICVErrors MIB element (see [IEEE.802-11.2007]).

   TKIP Local MIC Failures:   A 32-bit value representing the number of
      MIC failures encountered when checking the integrity of packets
      received from the station.  The value of this field comes from the
      IEEE 802.11 dot11RSNAStatsTKIPLocalMICFailures MIB element (see
      [IEEE.802-11.2007]).

   TKIP Remote MIC Failures:   A 32-bit value representing the number of
      MIC failures reported by the station encountered (possibly via the
      EAPOL-Key frame).  The value of this field comes from the IEEE
      802.11 dot11RSNAStatsTKIPRemoteMICFailures MIB element (see
      [IEEE.802-11.2007]).

   CCMP Replays:   A 32-bit value representing the number of CCMP MPDUs
      discarded by the replay detection mechanism.  The value of this
      field comes from the IEEE 802.11 dot11RSNACCMPReplays MIB element
      (see [IEEE.802-11.2007]).

   CCMP Decrypt Errors:   A 32-bit value representing the number of CCMP
      MDPUs discarded by the decryption algorithm.  The value of this
      field comes from the IEEE 802.11 dot11RSNACCMPDecryptErrors MIB
      element (see [IEEE.802-11.2007]).

   TKIP Replays:   A 32-bit value representing the number of TKIP
      Replays detected in frames received from the station.  The value
      of this field comes from the IEEE 802.11 dot11RSNAStatsTKIPReplays
      MIB element (see [IEEE.802-11.2007]).

6.13.  IEEE 802.11 Station

   The IEEE 802.11 Station message element accompanies the Add Station
   message element, and is used to deliver IEEE 802.11 station policy
   from the AC to the WTP.

   The latest IEEE 802.11 Station message element overrides any
   previously received message elements.

   If the QoS field is set, the WTP MUST observe and provide policing of
   the 802.11e priority tag to ensure that it does not exceed the value
   provided by the AC.






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      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Radio ID   |        Association ID         |     Flags     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           MAC Address                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |          MAC Address          |          Capabilities         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   WLAN ID     |Supported Rates|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1036 for IEEE 802.11 Station

   Length:   >= 14

   Radio ID:   An 8-bit value representing the radio, whose value is
      between one (1) and 31.

   Association ID:   A 16-bit value specifying the IEEE 802.11
      Association Identifier.

   Flags:   All implementations complying with this protocol MUST set to
      zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.

   MAC Address:   The station's MAC Address

   Capabilities:   A 16-bit field containing the IEEE 802.11
      Capabilities Information Field to use with the station.

   WLAN ID:   An 8-bit value specifying the WLAN Identifier.  The value
      MUST be between one (1) and 16.

   Supported Rates:   The variable-length field containing the supported
      rates to be used with the station, as found in the IEEE 802.11
      dot11OperationalRateSet MIB element (see [IEEE.802-11.2007]).
      This field MUST NOT exceed 126 octets and specifies the set of
      data rates at which the station may transmit data, where each
      octet represents a data rate.

6.14.  IEEE 802.11 Station QoS Profile

   The IEEE 802.11 Station QoS Profile message element contains the
   maximum IEEE 802.11e priority tag that may be used by the station.
   Any packet received that exceeds the value encoded in this message
   element MUST be tagged using the maximum value permitted by to the



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   user.  The priority tag MUST be between zero (0) and seven (7).  This
   message element MUST NOT be present without the IEEE 802.11 Station
   (see Section 6.13) message element.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                           MAC Address                         |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |          MAC Address          |         Reserved        |8021p|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1037 for IEEE 802.11 Station QoS Profile

   Length:   8

   MAC Address:   The station's MAC Address

   Reserved:   All implementations complying with this protocol MUST set
      to zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.

   8021p:   The maximum 802.1p priority value that the WTP will allow in
      the Traffic Identifier (TID) field in the extended 802.11e QoS
      Data header.

6.15.  IEEE 802.11 Station Session Key

   The IEEE 802.11 Station Session Key message element is sent by the AC
   to provision encryption keys, or to configure an access policy, on
   the WTP.  This message element MUST NOT be present without the IEEE
   802.11 Station (see Section 6.13) message element, and MUST NOT be
   sent if the WTP had not specifically advertised support for the
   requested encryption scheme, through the WTP Descriptor Message
   Element's Encryption Capabilities field (see Section 8.1).

   When the Key field is non-zero in length, the RSN Information Element
   MUST be sent along with the IEEE 802.11 Station Session Key in order
   to instruct the WTP on the usage of the Key field.  The WTP MUST
   observe the Authentication and Key Management (AKM) field of the RSN
   Information Element in order to identify the authentication protocol
   to be enforced with the station.

   If cryptographic services are provided at the WTP, the WTP MUST
   observe the algorithm dictated in the Pairwise Cipher Suite field of
   the RSN Information Element sent by the AC.  The RSN Information
   Element included here is the one sent by the AC in the third message



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   of the 4-Way Key Handshake, which specifies which cipher is to be
   applied to provide encryption and decryption services with the
   station.  The RSN Information Element is used to communicate any
   supported algorithm, including WEP, TKIP, and AES-CCMP.  In the case
   of static WEP keys, the RSN Information Element is still used to
   indicate the cryptographic algorithm even though no key exchange
   occurred.

   If the IEEE 802.11 Station Session Key message element's 'AKM-Only'
   bit is set, the WTP MUST drop all IEEE 802.11 packets that are not
   part of the Authentication and Key Management (AKM), such as EAP.
   Note that AKM-Only MAY be set while an encryption key is in force,
   requiring that the AKM packets be encrypted.  Once the station has
   successfully completed authentication via the AKM, the AC MUST send a
   new Add Station message element to remove the AKM-Only restriction,
   and optionally push the session key down to the WTP.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                           MAC Address                         |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |          MAC Address          |A|C|           Flags           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                         Pairwise TSC                          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |         Pairwise TSC          |         Pairwise RSC          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                         Pairwise RSC                          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Key...
       +-+-+-+-+-+-+-+-

   Type:   1038 for IEEE 802.11 Station Session Key

   Length:   >= 25

   MAC Address:   The station's MAC Address

   Flags:   All implementations complying with this protocol MUST set to
      zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.  The
      following bits are defined:







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      A:   The 1-bit AKM-Only field is set by the AC to inform the WTP
           that is MUST NOT accept any 802.11 Data Frames other than AKM
           frames.  This is the equivalent of the WTP's IEEE 802.1X port
           for the station to be in the closed state.  When set, the WTP
           MUST drop any non-IEEE 802.1X packets it receives from the
           station.

      C:   The 1-bit field is set by the AC to inform the WTP that
           encryption services will be provided by the AC.  When set,
           the WTP SHOULD police frames received from stations to ensure
           that they are properly encrypted as specified in the RSN
           Information Element, but does not need to take specific
           cryptographic action on the frame.  Similarly, for
           transmitted frames, the WTP only needs to forward already
           encrypted frames.  Since packets received by the WTP will be
           encrypted, the WTP cannot modify the contents of the packets,
           including modifying the DSCP markings of the encapsulated
           packet.  In this case, this function would be the
           responsibility of the AC.

   Pairwise TSC:   The 6-byte Transmit Sequence Counter (TSC) field to
      use for unicast packets transmitted to the station.

   Pairwise RSC:   The 6-byte Receive Sequence Counter (RSC) to use for
      unicast packets received from the station.

   Key:   The pairwise key the WTP is to use when encrypting traffic to/
      from the station.  The format of the keys differs based on the
      crypto algorithm used.  For unicast WEP keys, the Key field
      consists of the actual unicast encryption key (note, this is used
      when WEP is used in conjunction with 802.1X, and therefore a
      unicast encryption key exists).  When used with CCMP, the Key
      field includes the 128-bit Temporal Key.  When used with TKIP, the
      Key field includes the 256-bit Temporal Key (which consists of a
      128-bit key used as input for TKIP key mixing, and two 64-bit keys
      used for Michael).

6.16.  IEEE 802.11 Statistics

   The IEEE 802.11 Statistics message element is sent by the WTP to
   transmit its current statistics, and it contains the following
   fields.  All of the fields in this message element are set to zero
   upon WTP initialization.  The fields will roll over when they reach
   their maximum value of 4294967295.  Due to the nature of each counter
   representing different data points, the rollover event will vary






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   greatly across each field.  Applications or human operators using
   these counters need to be aware of the minimal possible times between
   rollover events in order to make sure that no consecutive rollover
   events are missed.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |                   Reserved                    |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Tx Fragment Count                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Multicast Tx Count                      |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                          Failed Count                         |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                          Retry Count                          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                      Multiple Retry Count                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                     Frame Duplicate Count                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       RTS Success Count                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       RTS Failure Count                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       ACK Failure Count                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Rx Fragment Count                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Multicast RX Count                      |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                        FCS Error  Count                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                        Tx Frame Count                         |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                       Decryption Errors                       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                  Discarded QoS Fragment Count                 |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                    Associated Station Count                   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                  QoS CF Polls Received Count                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                   QoS CF Polls Unused Count                   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                  QoS CF Polls Unusable Count                  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



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   Type:   1039 for IEEE 802.11 Statistics

   Length:   80

   Radio ID:   An 8-bit value representing the radio, whose value is
      between one (1) and 31.

   Reserved:   All implementations complying with this protocol MUST set
      to zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.

   Tx Fragment Count:   A 32-bit value representing the number of
      fragmented frames transmitted.  The value of this field comes from
      the IEEE 802.11 dot11TransmittedFragmentCount MIB element (see
      [IEEE.802-11.2007]).

   Multicast Tx Count:   A 32-bit value representing the number of
      multicast frames transmitted.  The value of this field comes from
      the IEEE 802.11 dot11MulticastTransmittedFrameCount MIB element
      (see [IEEE.802-11.2007]).

   Failed Count:   A 32-bit value representing the transmit excessive
      retries.  The value of this field comes from the IEEE 802.11
      dot11FailedCount MIB element (see [IEEE.802-11.2007]).

   Retry Count:   A 32-bit value representing the number of transmit
      retries.  The value of this field comes from the IEEE 802.11
      dot11RetryCount MIB element (see [IEEE.802-11.2007]).

   Multiple Retry Count:   A 32-bit value representing the number of
      transmits that required more than one retry.  The value of this
      field comes from the IEEE 802.11 dot11MultipleRetryCount MIB
      element (see [IEEE.802-11.2007]).

   Frame Duplicate Count:   A 32-bit value representing the duplicate
      frames received.  The value of this field comes from the IEEE
      802.11 dot11FrameDuplicateCount MIB element (see
      [IEEE.802-11.2007]).

   RTS Success Count:   A 32-bit value representing the number of
      successfully transmitted Ready To Send (RTS).  The value of this
      field comes from the IEEE 802.11 dot11RTSSuccessCount MIB element
      (see [IEEE.802-11.2007]).







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   RTS Failure Count:   A 32-bit value representing the failed
      transmitted RTS.  The value of this field comes from the IEEE
      802.11 dot11RTSFailureCount MIB element (see [IEEE.802-11.2007]).

   ACK Failure Count:   A 32-bit value representing the number of failed
      acknowledgements.  The value of this field comes from the IEEE
      802.11 dot11ACKFailureCount MIB element (see [IEEE.802-11.2007]).

   Rx Fragment Count:   A 32-bit value representing the number of
      fragmented frames received.  The value of this field comes from
      the IEEE 802.11 dot11ReceivedFragmentCount MIB element (see
      [IEEE.802-11.2007]).

   Multicast RX Count:   A 32-bit value representing the number of
      multicast frames received.  The value of this field comes from the
      IEEE 802.11 dot11MulticastReceivedFrameCount MIB element (see
      [IEEE.802-11.2007]).

   FCS Error Count:   A 32-bit value representing the number of FCS
      failures.  The value of this field comes from the IEEE 802.11
      dot11FCSErrorCount MIB element (see [IEEE.802-11.2007]).

   Decryption Errors:   A 32-bit value representing the number of
      Decryption errors that occurred on the WTP.  Note that this field
      is only valid in cases where the WTP provides encryption/
      decryption services.  The value of this field comes from the IEEE
      802.11 dot11WEPUndecryptableCount MIB element (see
      [IEEE.802-11.2007]).

   Discarded QoS Fragment Count:   A 32-bit value representing the
      number of discarded QoS fragments received.  The value of this
      field comes from the IEEE 802.11 dot11QoSDiscardedFragmentCount
      MIB element (see [IEEE.802-11.2007]).

   Associated Station Count:   A 32-bit value representing the number of
      number of associated stations.  The value of this field comes from
      the IEEE 802.11 dot11AssociatedStationCount MIB element (see
      [IEEE.802-11.2007]).

   QoS CF Polls Received Count:   A 32-bit value representing the number
      of (+)CF-Polls received.  The value of this field comes from the
      IEEE 802.11 dot11QosCFPollsReceivedCount MIB element (see
      [IEEE.802-11.2007]).

   QoS CF Polls Unused Count:   A 32-bit value representing the number
      of (+)CF-Polls that have been received, but not used.  The value
      of this field comes from the IEEE 802.11
      dot11QosCFPollsUnusedCount MIB element (see [IEEE.802-11.2007]).



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   QoS CF Polls Unusable Count:   A 32-bit value representing the number
      of (+)CF-Polls that have been received, but could not be used due
      to the Transmission Opportunity (TXOP) size being smaller than the
      time that is required for one frame exchange sequence.  The value
      of this field comes from the IEEE 802.11
      dot11QosCFPollsUnusableCount MIB element (see [IEEE.802-11.2007]).

6.17.  IEEE 802.11 Supported Rates

   The IEEE 802.11 Supported Rates message element is sent by the WTP to
   indicate the rates that it supports, and contains the following
   fields.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |               Supported Rates...
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1040 for IEEE 802.11 Supported Rates

   Length:   >= 3

   Radio ID:   An 8-bit value representing the radio, whose value is
      between one (1) and 31.

   Supported Rates:   The WTP includes the Supported Rates that its
      hardware supports.  The format is identical to the Rate Set
      message element and is between 2 and 8 bytes in length.

6.18.  IEEE 802.11 Tx Power

   The IEEE 802.11 Tx Power message element value is bi-directional.
   When sent by the WTP, it contains the current power level of the
   radio in question.  When sent by the AC, it contains the power level
   to which the WTP MUST adhere.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |    Reserved   |        Current Tx Power       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1041 for IEEE 802.11 Tx Power







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   Length:   4

   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.

   Reserved:   All implementations complying with this protocol MUST set
      to zero any bits that are reserved in the version of the protocol
      supported by that implementation.  Receivers MUST ignore all bits
      not defined for the version of the protocol they support.

   Current Tx Power:   This attribute contains the current transmit
      output power in mW, as described in the dot11CurrentTxPowerLevel
      MIB variable, see [IEEE.802-11.2007].

6.19.  IEEE 802.11 Tx Power Level

   The IEEE 802.11 Tx Power Level message element is sent by the WTP and
   contains the different power levels supported.  The values found in
   this message element are found in the IEEE 802.11
   Dot11PhyTxPowerEntry MIB table, see [IEEE.802-11.2007].

   The value field contains the following:

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |   Num Levels  |        Power Level [n]        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1042 for IEEE 802.11 Tx Power Level

   Length:   >= 4

   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.

   Num Levels:   The number of power level attributes.  The value of
      this field comes from the IEEE 802.11
      dot11NumberSupportedPowerLevels MIB element (see
      [IEEE.802-11.2007]).

   Power Level:   Each power level field contains a supported power
      level, in mW.  The value of this field comes from the
      corresponding IEEE 802.11 dot11TxPowerLevel[n] MIB element, see
      [IEEE.802-11.2007].






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6.20.  IEEE 802.11 Update Station QoS

   The IEEE 802.11 Update Station QoS message element is used to change
   the Quality of Service policy on the WTP for a given station.  The
   QoS tags included in this message element are to be applied to
   packets received at the WTP from the station indicated through the
   MAC Address field.  This message element overrides the default values
   provided through the IEEE 802.11 WTP Quality of Service message
   element (see Section 6.22).  Any tagging performed by the WTP MUST be
   directly applied to the packets received from the station, as well as
   the CAPWAP tunnel, if the packets are tunneled to the AC.  See
   Section 2.6 for more information.

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |                  MAC Address                  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |          MAC Address          |       QoS Sub-Element...      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1043 for IEEE 802.11 Update Station QoS

   Length:   8

   Radio ID:   The Radio Identifier, whose value is between one (1) and
      31, typically refers to some interface index on the WTP.

   MAC Address:   The station's MAC Address.

   QoS Sub-Element:   The IEEE 802.11 WTP Quality of Service message
      element contains four QoS sub-elements, one for every QoS profile.
      The order of the QoS profiles are Voice, Video, Best Effort, and
      Background.

      0                   1
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Reserved|8021p|RSV| DSCP Tag  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


      Reserved:   All implementations complying with this protocol MUST
         set to zero any bits that are reserved in the version of the
         protocol supported by that implementation.  Receivers MUST
         ignore all bits not defined for the version of the protocol
         they support.




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      8021p:   The 3-bit 802.1p priority value to use if packets are to
         be IEEE 802.1p tagged.  This field is used only if the 'P' bit
         in the WTP Quality of Service message element was set;
         otherwise, its contents MUST be ignored.

      RSV:   All implementations complying with this protocol MUST set
         to zero any bits that are reserved in the version of the
         protocol supported by that implementation.  Receivers MUST
         ignore all bits not defined for the version of the protocol
         they support.

      DSCP Tag:   The 6-bit DSCP label to use if packets are eligible to
         be DSCP tagged, specifically an IPv4 or IPv6 packet (see
         [RFC2474]).  This field is used only if the 'D' bit in the WTP
         Quality of Service message element was set; otherwise, its
         contents MUST be ignored.

6.21.  IEEE 802.11 Update WLAN

   The IEEE 802.11 Update WLAN message element is used by the AC to
   define a wireless LAN on the WTP.  The inclusion of this message
   element MUST also include the IEEE 802.11 Information Element message
   element, containing the following 802.11 IEs:

   Power Constraint information element

   WPA information element  [WPA]

   RSN information element

   Enhanced Distributed Channel Access (EDCA) Parameter Set information
      element

   QoS Capability information element

   WMM information element  [WMM]

   These IEEE 802.11 Information Elements are stored by the WTP and
   included in any Probe Responses and Beacons generated, as specified
   in the IEEE 802.11 standard [IEEE.802-11.2007].

   If cryptographic services are provided at the WTP, the WTP MUST
   observe the algorithm dictated in the Group Cipher Suite field of the
   RSN Information Element sent by the AC.  The RSN Information Element
   is used to communicate any supported algorithm, including WEP, TKIP,
   and AES-CCMP.  In the case of static WEP keys, the RSN Information
   Element is still used to indicate the cryptographic algorithm even
   though no key exchange occurred.



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   The message element uses the following format:

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |     WLAN ID   |           Capability          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   Key Index   |   Key Status  |           Key Length          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                             Key...                            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1044 for IEEE 802.11 Update WLAN

   Length:   >= 8

   Radio ID:   An 8-bit value representing the radio, whose value is
      between one (1) and 31.

   WLAN ID:   An 8-bit value specifying the WLAN Identifier.  The value
      MUST be between one (1) and 16.

   Capability:   A 16-bit value containing the Capability information
      field to be advertised by the WTP in the Probe Request and Beacon
      frames.  Each bit of the Capability field represents a different
      WTP capability, which are described in detail in
      [IEEE.802-11.2007].  The format of the field is:

        0                   1
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |E|I|C|F|P|S|B|A|M|Q|T|D|V|O|K|L|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      E (ESS):   The AC MUST set the Extended Service Set (ESS) subfield
        to 1.

      I (IBSS):   The AC MUST set the Independent Basic Service Set
        (IBSS) subfield to 0.

      C (CF-Pollable):   The AC sets the Contention Free Pollable (CF-
        Pollable) subfield based on the table found in
        [IEEE.802-11.2007].

      F (CF-Poll Request):   The AC sets the CF-Poll Request subfield
        based on the table found in [IEEE.802-11.2007].





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      P (Privacy):   The AC sets the Privacy subfield based on the
        confidentiality requirements of the WLAN, as defined in
        [IEEE.802-11.2007].

      S (Short Preamble):   The AC sets the Short Preamble subfield
        based on whether the use of short preambles are permitted on the
        WLAN, as defined in [IEEE.802-11.2007].

      B (PBCC):   The AC sets the Packet Binary Convolutional Code
        (PBCC) modulation option subfield based on whether the use of
        PBCC is permitted on the WLAN, as defined in [IEEE.802-11.2007].

      A (Channel Agility):   The AC sets the Channel Agility subfield
        based on whether the WTP is capable of supporting the High Rate
        Direct Sequence Spread Spectrum (HR/DSSS), as defined in
        [IEEE.802-11.2007].

      M (Spectrum Management):   The AC sets the Spectrum Management
        subfield according to the value of the
        dot11SpectrumManagementRequired MIB variable, as defined in
        [IEEE.802-11.2007].

      Q (QoS):   The AC sets the Quality of Service (QoS) subfield based
        on the table found in [IEEE.802-11.2007].

      T (Short Slot Time):   The AC sets the Short Slot Time subfield
        according to the value of the WTP's currently used slot time
        value, as defined in [IEEE.802-11.2007].

      D (APSD):   The AC sets the APSD subfield according to the value
        of the dot11APSDOptionImplemented Management Information Base
        (MIB) variable, as defined in [IEEE.802-11.2007].

      V (Reserved):   The AC sets the Reserved subfield to zero, as
        defined in [IEEE.802-11.2007].

      O (DSSS-OFDM):   The AC sets the DSSS-OFDM subfield to indicate
        the use of Direct Sequence Spread Spectrum with Orthogonal
        Frequency Division Multiplexing (DSSS-OFDM), as defined in
        [IEEE.802-11.2007].

      K (Delayed Block ACK):   The AC sets the Delayed Block ACK
        subfield according to the value of the
        dot11DelayedBlockAckOptionImplemented MIB variable, as defined
        in [IEEE.802-11.2007].






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      L (Immediate Block ACK):   The AC sets the Delayed Block ACK
        subfield according to the value of the
        dot11ImmediateBlockAckOptionImplemented MIB variable, as defined
        in [IEEE.802-11.2007].

   Key-Index:   The Key-Index associated with the key.

   Key Status:   A 1-byte value that specifies the state and usage of
      the key that has been included.  The following values describe the
      key usage and its status:

      0 -  A value of zero, with the inclusion of the RSN Information
           Element means that the WLAN uses per-station encryption keys,
           and therefore the key in the 'Key' field is only used for
           multicast traffic.

      1 -  When set to one, the WLAN employs a shared WEP key, also
           known as a static WEP key, and uses the encryption key for
           both unicast and multicast traffic for all stations.

      2 -  The value of 2 indicates that the AC will begin rekeying the
           GTK with the STA's in the BSS.  It is only valid when IEEE
           802.11 is enabled as the security policy for the BSS.

      3 -  The value of 3 indicates that the AC has completed rekeying
           the GTK and broadcast packets no longer need to be duplicated
           and transmitted with both GTK's.

   Key Length:   A 16-bit value representing the length of the Key
      field.

   Key:   A Session Key, whose length is known via the Key Length field,
      used to provide data privacy.  For static WEP keys, which is true
      when the 'Key Status' bit is set to one, this key is used for both
      unicast and multicast traffic.  For encryption schemes that employ
      a separate encryption key for unicast and multicast traffic, the
      key included here only applies to multicast data, and the cipher
      suite is specified in an accompanied RSN Information Element.  In
      these scenarios, the key, and cipher information, is communicated
      via the Add Station message element, see Section 4.6.8 in
      [RFC5415].  When used with WEP, the Key field includes the
      broadcast key.  When used with CCMP, the Key field includes the
      128-bit Group Temporal Key.  When used with TKIP, the Key field
      includes the 256-bit Group Temporal Key (which consists of a 128-
      bit key used as input for TKIP key mixing, and two 64-bit keys
      used for Michael).





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6.22.  IEEE 802.11 WTP Quality of Service

   The IEEE 802.11 WTP Quality of Service message element value is sent
   by the AC to the WTP to communicate Quality of Service configuration
   information.  The QoS tags included in this message element are the
   default QoS values to be applied to packets received by the WTP from
   stations on a particular radio.  Any tagging performed by the WTP
   MUST be directly applied to the packets received from the station, as
   well as the CAPWAP tunnel, if the packets are tunneled to the AC.
   See Section 2.6 for more information.

        0                   1                   2                   3
        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |Tagging Policy |       QoS Sub-Element ...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1045 for IEEE 802.11 WTP Quality of Service

   Length:   34

   Radio ID:   The Radio Identifier, whose value is between one (1) and
      31, typically refers to some interface index on the WTP.

   Tagging Policy:   A bit field indicating how the WTP is to mark
      packets for QoS purposes.  The required WTP behavior is defined in
      Section 2.6.1.  The field has the following format:

         0 1 2 3 4 5 6 7
        +-+-+-+-+-+-+-+-+
        |Rsvd |P|Q|D|O|I|
        +-+-+-+-+-+-+-+-+

      Rsvd:  A set of reserved bits for future use.  All implementations
         complying with this protocol MUST set to zero any bits that are
         reserved in the version of the protocol supported by that
         implementation.  Receivers MUST ignore all bits not defined for
         the version of the protocol they support.

      P:   When set, the WTP is to employ the 802.1p QoS mechanism (see
           Section 2.6.1.1), and the WTP is to use the 'Q' bit.

      Q:   When the 'P' bit is set, the 'Q' bit is used by the AC to
           communicate to the WTP how 802.1p QoS is to be enforced.
           Details on the behavior of the 'Q' bit are specified in
           Section 2.6.1.1.





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      D:   When set, the WTP is to employ the DSCP QoS mechanism (see
           Section 2.6.1.2), and the WTP is to use the 'O' and 'I' bits.

      O:   When the 'D' bit is set, the 'O' bit is used by the AC to
           communicate to the WTP how DSCP QoS is to be enforced on the
           outer (tunneled) header.  Details on the behavior of the 'O'
           bit are specified in Section 2.6.1.2.

      I:   When the 'D' bit is set, the 'I' bit is used by the AC to
           communicate to the WTP how DSCP QoS is to be enforced on the
           station's packet (inner) header.  Details on the behavior of
           the 'I' bit are specified in Section 2.6.1.2.

   QoS Sub-Element:   The IEEE 802.11 WTP Quality of Service message
      element contains four QoS sub-elements, one for every QoS profile.
      The order of the QoS profiles are Voice, Video, Best Effort, and
      Background.

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Queue Depth  |             CWMin             |     CWMax     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     CWMax     |     AIFS      | Reserved|8021p|RSV| DSCP Tag  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Queue Depth:   The number of packets that can be on the specific
         QoS transmit queue at any given time.

      CWMin:   The Contention Window minimum (CWmin) value for the QoS
         transmit queue.  The value of this field comes from the IEEE
         802.11 dot11EDCATableCWMin MIB element (see
         [IEEE.802-11.2007]).

      CWMax:   The Contention Window maximum (CWmax) value for the QoS
         transmit queue.  The value of this field comes from the IEEE
         802.11 dot11EDCATableCWMax MIB element (see
         [IEEE.802-11.2007]).

      AIFS:   The Arbitration Inter Frame Spacing (AIFS) to use for the
         QoS transmit queue.  The value of this field comes from the
         IEEE 802.11 dot11EDCATableAIFSN MIB element (see
         [IEEE.802-11.2007]).








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      Reserved:   All implementations complying with this protocol MUST
         set to zero any bits that are reserved in the version of the
         protocol supported by that implementation.  Receivers MUST
         ignore all bits not defined for the version of the protocol
         they support.

      8021p:   The 3-bit 802.1p priority value to use if packets are to
         be IEEE 802.1p tagged.  This field is used only if the 'P' bit
         is set; otherwise, its contents MUST be ignored.

      RSV:   All implementations complying with this protocol MUST set
         to zero any bits that are reserved in the version of the
         protocol supported by that implementation.  Receivers MUST
         ignore all bits not defined for the version of the protocol
         they support.

      DSCP Tag:   The 6-bit DSCP label to use if packets are eligible to
         be DSCP tagged, specifically an IPv4 or IPv6 packet (see
         [RFC2474]).  This field is used only if the 'D' bit is set;
         otherwise, its contents MUST be ignored.

6.23.  IEEE 802.11 WTP Radio Configuration

   The IEEE 802.11 WTP WLAN Radio Configuration message element is used
   by the AC to configure a Radio on the WTP, and by the WTP to deliver
   its radio configuration to the AC.  The message element value
   contains the following fields:

         0                   1                   2                   3
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    Radio ID   |Short Preamble| Num of BSSIDs |  DTIM Period  |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                            BSSID                              |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |          BSSID                |      Beacon Period            |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                        Country String                         |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1046 for IEEE 802.11 WTP WLAN Radio Configuration

   Length:   16

   Radio ID:   An 8-bit value representing the radio to configure, whose
      value is between one (1) and 31.





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   Short Preamble:   An 8-bit value indicating whether short preamble is
      supported.  The following enumerated values are currently
      supported:

      0 -  Short preamble not supported.

      1 -  Short preamble is supported.

   BSSID:   The WLAN Radio's base MAC Address.

   Number of BSSIDs:   This attribute contains the maximum number of
      BSSIDs supported by the WTP.  This value restricts the number of
      logical networks supported by the WTP, and is between 1 and 16.

   DTIM Period:   This attribute specifies the number of Beacon
      intervals that elapse between transmission of Beacons frames
      containing a Traffic Indication Map (TIM) element whose Delivery
      Traffic Indication Message (DTIM) Count field is 0.  This value is
      transmitted in the DTIM Period field of Beacon frames.  The value
      of this field comes from the IEEE 802.11 dot11DTIMPeriod MIB
      element (see [IEEE.802-11.2007]).

   Beacon Period:   This attribute specifies the number of Time Unit
      (TU) that a station uses for scheduling Beacon transmissions.
      This value is transmitted in Beacon and Probe Response frames.
      The value of this field comes from the IEEE 802.11
      dot11BeaconPeriod MIB element (see [IEEE.802-11.2007]).

   Country String:   This attribute identifies the country in which the
      station is operating.  The value of this field comes from the IEEE
      802.11 dot11CountryString MIB element (see [IEEE.802-11.2007]).
      Some regulatory domains do not allow WTPs to have user
      configurable country string, and require that it be a fixed value
      during the manufacturing process.  Therefore, WTP vendors that
      wish to allow for the configuration of this field will need to
      validate this behavior during its radio certification process.
      Other WTP vendors may simply wish to treat this WTP configuration
      parameter as read-only.  The country strings can be found in
      [ISO.3166-1].

      The WTP and AC MAY ignore the value of this field, depending upon
      regulatory requirements, for example to avoid classification as a
      Software-Defined Radio.  When this field is used, the first two
      octets of this string is the two-character country string as
      described in [ISO.3166-1], and the third octet MUST either be a
      space, 'O', 'I', or X' as defined below.  When the value of the





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      third octet is 255 (HEX 0xff), the country string field is not
      used, and MUST be ignored.  The following are the possible values
      for the third octet:

      1.   an ASCII space character, if the regulations under which the
           station is operating encompass all environments in the
           country,

      2.   an ASCII 'O' character, if the regulations under which the
           station is operating are for an outdoor environment only, or

      3.   an ASCII 'I' character, if the regulations under which the
           station is operating are for an indoor environment only,

      4.   an ASCII 'X' character, if the station is operating under a
           non-country entity.  The first two octets of the non-country
           entity shall be two ASCII 'XX' characters,

      5.   a HEX 0xff character means that the country string field is
           not used and MUST be ignored.

      Note that the last byte of the Country String MUST be set to NULL.

6.24.  IEEE 802.11 WTP Radio Fail Alarm Indication

   The IEEE 802.11 WTP Radio Fail Alarm Indication message element is
   sent by the WTP to the AC when it detects a radio failure.

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |     Type      |    Status     |      Pad      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Type:   1047 for IEEE 802.11 WTP Radio Fail Alarm Indication

   Length:   4

   Radio ID:   The Radio Identifier, whose value is between one (1) and
      31, typically refers to some interface index on the WTP.

   Type:   The type of radio failure detected.  The following enumerated
      values are supported:

      1 -  Receiver

      2 -  Transmitter




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   Status:   An 8-bit boolean indicating whether the radio failure is
      being reported or cleared.  A value of zero is used to clear the
      event, while a value of one is used to report the event.

   Pad:   All implementations complying with version zero of this
      protocol MUST set these bits to zero.  Receivers MUST ignore all
      bits not defined for the version of the protocol they support.

6.25.  IEEE 802.11 WTP Radio Information

   The IEEE 802.11 WTP Radio Information message element is used to
   communicate the radio information for each IEEE 802.11 radio in the
   WTP.  The Discovery Request message, Primary Discovery Request
   message, and Join Request message MUST include one such message
   element per radio in the WTP.  The Radio-Type field is used by the AC
   in order to determine which IEEE 802.11 technology specific binding
   is to be used with the WTP.

   The message element contains two fields, as shown below.

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Radio ID    |                  Radio Type                   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Radio Type   |
     +-+-+-+-+-+-+-+-+

   Type:   1048 for IEEE 802.11 WTP Radio Information

   Length:   5

   Radio ID:   The Radio Identifier, whose value is between one (1) and
      31, which typically refers to an interface index on the WTP.

   Radio Type:   The type of radio present.  Note this is a bit field
      that is used to specify support for more than a single type of
      PHY/MAC.  The field has the following format:

         0 1 2 3 4 5 6 7
        +-+-+-+-+-+-+-+-+
        |Reservd|N|G|A|B|
        +-+-+-+-+-+-+-+-+








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      Reservd:  A set of reserved bits for future use.  All
         implementations complying with this protocol MUST set to zero
         any bits that are reserved in the version of the protocol
         supported by that implementation.  Receivers MUST ignore all
         bits not defined for the version of the protocol they support.

      N:   An IEEE 802.11n radio.

      G:   An IEEE 802.11g radio.

      A:   An IEEE 802.11a radio.

      B:   An IEEE 802.11b radio.

7.  IEEE 802.11 Binding WTP Saved Variables

   This section contains the IEEE 802.11 binding specific variables that
   SHOULD be saved in non-volatile memory on the WTP.

7.1.  IEEE80211AntennaInfo

   The WTP-per-radio antenna configuration, defined in Section 6.2.

7.2.  IEEE80211DSControl

   The WTP-per-radio Direct Sequence Control configuration, defined in
   Section 6.5.

7.3.  IEEE80211MACOperation

   The WTP-per-radio MAC Operation configuration, defined in
   Section 6.7.

7.4.  IEEE80211OFDMControl

   The WTP-per-radio OFDM MAC Operation configuration, defined in
   Section 6.10.

7.5.  IEEE80211Rateset

   The WTP-per-radio Basic Rate Set configuration, defined in
   Section 6.11.

7.6.  IEEE80211TxPower

   The WTP-per-radio Transmit Power configuration, defined in
   Section 6.18.




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7.7.  IEEE80211QoS

   The WTP-per-radio Quality of Service configuration, defined in
   Section 6.22.

7.8.  IEEE80211RadioConfig

   The WTP-per-radio Radio Configuration, defined in Section 6.23.

8.  Technology Specific Message Element Values

   This section lists IEEE 802.11-specific values for the generic CAPWAP
   message elements that include fields whose values are technology
   specific.

8.1.  WTP Descriptor Message Element, Encryption Capabilities Field

   This specification defines two new bits for the WTP Descriptor's
   Encryption Capabilities field, as defined in [RFC5415].  Note that
   only the bits defined in this specification are described below.  WEP
   is not explicitly advertised as a WTP capability since all WTPs are
   expected to support the encryption cipher.  The format of the
   Encryption Capabilities field is:

                             1
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |                       |A|T|   |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   A:   WTP supports AES-CCMP, as defined in [IEEE.802-11.2007].

   T:   WTP supports TKIP and Michael, as defined in [IEEE.802-11.2007]
        and [WPA], respectively.

9.  Security Considerations

   This section describes security considerations for using IEEE 802.11
   with the CAPWAP protocol.  A complete threat analysis of the CAPWAP
   protocol can also be found in [RFC5418].

9.1.  IEEE 802.11 Security

   When used with an IEEE 802.11 infrastructure with WEP encryption, the
   CAPWAP protocol does not add any new vulnerabilities.  Derived
   Session Keys between the STA and WTP can be compromised, resulting in





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   many well-documented attacks.  Implementers SHOULD discourage the use
   of WEP and encourage the use of technically-sound cryptographic
   solutions such as those in an IEEE 802.11 RSN.

   STA authentication is performed using IEEE 802.lX, and consequently
   EAP.  Implementers SHOULD use EAP methods meeting the requirements
   specified [RFC4017].

   When used with IEEE 802.11 RSN security, the CAPWAP protocol may
   introduce new vulnerabilities, depending on whether the link security
   (packet encryption and integrity verification) is provided by the WTP
   or the AC.  When the link security function is provided by the AC, no
   new security concerns are introduced.

   However, when the WTP provides link security, a new vulnerability
   will exist when the following conditions are true:

   o  The client is not the first to associate to the WTP/ESSID (i.e.,
      other clients are associated), a GTK already exists, and

   o  traffic has been broadcast under the existing GTK.

   Under these circumstances, the receive sequence counter (KeyRSC)
   associated with the GTK is non-zero, but because the AC anchors the
   4-way handshake with the client, the exact value of the KeyRSC is not
   known when the AC constructs the message containing the GTK.  The
   client will update its Key RSC value to the current valid KeyRSC upon
   receipt of a valid multicast/broadcast message, but prior to this,
   previous multicast/broadcast traffic that was secured with the
   existing GTK may be replayed, and the client will accept this traffic
   as valid.

   Typically, busy networks will produce numerous multicast or broadcast
   frames per second, so the window of opportunity with respect to such
   replay is expected to be very small.  In most conditions, it is
   expected that replayed frames could be detected (and logged) by the
   WTP.

   The only way to completely close this window is to provide the exact
   KeyRSC value in message 3 of the 4-way handshake; any other approach
   simply narrows the window to varying degrees.  Given the low relative
   threat level this presents, the additional complexity introduced by
   providing the exact KeyRSC value is not warranted.  That is, this
   specification provides for a calculated risk in this regard.







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   The AC SHOULD use an RSC of 0 when computing message-3 of the 4-way
   802.11i handshake, unless the AC has knowledge of a more optimal RSC
   value to use.  Mechanisms for determining a more optimal RSC value
   are outside the scope of this specification.

10.  IANA Considerations

   This section details the actions IANA has taken per this
   specification.  There are numerous registries that have been be
   created, and the contents, document action (see [RFC5226], and
   registry format are all included below.  Note that in cases where bit
   fields are referred to, the bit numbering is left to right, where the
   leftmost bit is labeled as bit zero (0).

10.1.  CAPWAP Wireless Binding Identifier

   This specification requires a value assigned from the Wireless
   Binding Identifier namespace, defined in [RFC5415]. (1) has been
   assigned (see Section 2.1, as it is used in implementations.

10.2.  CAPWAP IEEE 802.11 Message Types

   IANA created a new sub-registry in the existing CAPWAP Message Type
   registry, which is defined in [RFC5415].

   IANA created and maintains the CAPWAP IEEE 802.11 Message Types
   sub-registry for all message types whose Enterprise Number is set to
   13277.  The namespace is 8 bits (3398912-3399167), where the value
   3398912 is reserved and must not be assigned.  The values 3398913 and
   3398914 are allocated in this specification, and can be found in
   Section 3.  Any new assignments of a CAPWAP IEEE 802.11 Message Type
   (whose Enterprise Number is set to 13277) require an Expert Review.
   The format of the registry maintained by IANA is as follows:

           CAPWAP IEEE 802.11               Message Type     Reference
           Control Message                     Value

10.3.  CAPWAP Message Element Type

   This specification defines new values to be registered to the
   existing CAPWAP Message Element Type registry, defined in [RFC5415].
   The values used in this document, 1024 through 1048, as listed in
   Figure 8 are recommended as implementations already exist that make
   use of these values.







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10.4.  IEEE 802.11 Key Status

   The Key Status field in the IEEE 802.11 Add WLAN message element (see
   Section 6.1) and IEEE 802.11 Update WLAN message element (see
   Section 6.21) is used to provide information about the status of the
   keying exchange.  This document defines four values, zero (0) through
   three (3), and the remaining values (4-255) are controlled and
   maintained by IANA and requires an Expert Review.

10.5.  IEEE 802.11 QoS

   The QoS field in the IEEE 802.11 Add WLAN message element (see
   Section 6.1) is used to configure a QoS policy for the WLAN.  The
   namespace is 8 bits (0-255), where the values zero (0) through three
   (3) are allocated in this specification, and can be found in
   Section 6.1.  This namespace is managed by IANA and assignments
   require an Expert Review.  IANA created the IEEE 802.11 QoS registry,
   whose format is:

           IEEE 802.11 QoS                  Type Value       Reference

10.6.  IEEE 802.11 Auth Type

   The Auth Type field in the IEEE 802.11 Add WLAN message element (see
   Section 6.1) is 8 bits and is used to configure the IEEE 802.11
   authentication policy for the WLAN.  The namespace is 8 bits (0-255),
   where the values zero (0) and one (1) are allocated in this
   specification, and can be found in Section 6.1.  This namespace is
   managed by IANA and assignments require an Expert Review.  IANA
   created the IEEE 802.11 Auth Type registry, whose format is:

           IEEE 802.11 Auth Type            Type Value       Reference

10.7.  IEEE 802.11 Antenna Combiner

   The Combiner field in the IEEE 802.11 Antenna message element (see
   Section 6.2) is used to provide information about the WTP's antennas.
   The namespace is 8 bits (0-255), where the values one (1) through
   four (4) are allocated in this specification, and can be found in
   Section 6.2.  This namespace is managed by IANA and assignments
   require an Expert Review.  IANA created the IEEE 802.11 Antenna
   Combiner registry, whose format is:

           IEEE 802.11 Antenna Combiner     Type Value       Reference







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10.8.  IEEE 802.11 Antenna Selection

   The Antenna Selection field in the IEEE 802.11 Antenna message
   element (see Section 6.2) is used to provide information about the
   WTP's antennas.  The namespace is 8 bits (0-255), where the values
   zero (0) is reserved and used and the values one (1) through two (2)
   are allocated in this specification, and can be found in Section 6.2.
   This namespace is managed by IANA and assignments require an Expert
   Review.  IANA created the IEEE 802.11 Antenna Selection registry,
   whose format is:

           IEEE 802.11 Antenna Selection    Type Value       Reference

10.9.  IEEE 802.11 Session Key Flags

   The flags field in the IEEE 802.11 Station Session Key message
   element (see Section 6.15) is 16 bits and is used to configure the
   session key association with the mobile device.  This specification
   defines bits zero (0) and one (1), while bits two (2) through fifteen
   are reserved.  The reserved bits are managed by IANA and assignment
   requires an Expert Review.  IANA created the IEEE 802.11 Session Key
   Flags registry, whose format is:

           IEEE 802.11 Station Session Key   Bit Position    Reference

10.10.  IEEE 802.11 Tagging Policy

   The Tagging Policy field in the IEEE 802.11 WTP Quality of Service
   message element (see Section 6.22) is 8 bits and is used to specify
   how the CAPWAP Data Channel packets are to be tagged.  This
   specification defines bits three (3) through seven (7).  The
   remaining bits are managed by IANA and assignment requires an Expert
   Review.  IANA created the IEEE 802.11 Tagging Policy registry, whose
   format is:

           IEEE 802.11 Tagging Policy        Bit Position    Reference

10.11.  IEEE 802.11 WTP Radio Fail

   The Type field in the IEEE 802.11 WTP Radio Fail Alarm Indication
   message element (see Section 6.24) is used to provide information on
   why a WTP's radio has failed.  The namespace is 8 bits (0-255), where
   the value zero (0) is reserved and unused, while the values one (1)
   and two (2) are allocated in this specification, and can be found in
   Section 6.24.  This namespace is managed by IANA and assignments
   require an Expert Review.  IANA created the IEEE 802.11 WTP Radio
   Fail registry, whose format is:




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           IEEE 802.11 WTP Radio Fail       Type Value       Reference

10.12.  IEEE 802.11 WTP Radio Type

   The Radio Type field in the IEEE 802.11 WTP Radio Information message
   element (see Section 6.25) is 8 bits and is used to provide
   information about the WTP's radio type.  This specification defines
   bits four (4) through seven (7).  The remaining bits are managed by
   IANA and assignment requires an Expert Review.  IANA created the IEEE
   802.11 WTP Radio Type registry, whose format is:

           IEEE 802.11 WTP Radio Type        Bit Position    Reference

10.13.  WTP Encryption Capabilities

   The WTP Encryption Capabilities field in the WTP Descriptor message
   element (see Section 8.1) is 16 bits and is used by the WTP to
   indicate its IEEE 802.11 encryption capabilities.  This specification
   defines bits 12 and 13.  The reserved bits are managed by IANA and
   assignment requires an Expert Review.  IANA created the IEEE 802.11
   Encryption Capabilities registry, whose format is:

          IEEE 802.11 Encryption Capabilities  Bit Position    Reference

11.  Acknowledgments

   The following individuals are acknowledged for their contributions to
   this binding specification: Puneet Agarwal, Charles Clancy, Pasi
   Eronen, Saravanan Govindan, Scott Kelly, Peter Nilsson, Bob O'Hara,
   David Perkins, Margaret Wasserman, and Yong Zhang.

12.  References

12.1.  Normative References

   [RFC2119]           Bradner, S., "Key words for use in RFCs to
                       Indicate Requirement Levels", BCP 14, RFC 2119,
                       March 1997.

   [RFC2474]           Nichols, K., Blake, S., Baker, F., and D. Black,
                       "Definition of the Differentiated Services Field
                       (DS Field) in the IPv4 and IPv6 Headers",
                       RFC 2474, December 1998.

   [RFC3246]           Davie, B., Charny, A., Bennet, J., Benson, K., Le
                       Boudec, J., Courtney, W., Davari, S., Firoiu, V.,
                       and D. Stiliadis, "An Expedited Forwarding PHB
                       (Per-Hop Behavior)", RFC 3246, March 2002.



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   [RFC3168]           Ramakrishnan, K., Floyd, S., and D. Black, "The
                       Addition of Explicit Congestion Notification
                       (ECN) to IP", RFC 3168, September 2001.

   [RFC3748]           Aboba, B., Blunk, L., Vollbrecht, J., Carlson,
                       J., and H. Levkowetz, "Extensible Authentication
                       Protocol (EAP)", RFC 3748, June 2004.

   [RFC5226]           Narten, T. and H. Alvestrand, "Guidelines for
                       Writing an IANA Considerations Section in RFCs",
                       BCP 26, RFC 5226, May 2008.

   [FIPS.197.2001]     National Institute of Standards and Technology,
                       "Advanced Encryption Standard (AES)", FIPS PUB
                       197, November 2001, <http://csrc.nist.gov/
                       publications/fips/fips197/fips-197.pdf>.

   [ISO.3166-1]        ISO Standard, "International Organization for
                       Standardization, Codes for the representation of
                       names of countries and their subdivisions - Part
                       1: Country codes", ISO Standard 3166-1:1997,
                       1997.

   [IEEE.802-11.2007]  "Information technology - Telecommunications and
                       information exchange between systems - Local and
                       metropolitan area networks - Specific
                       requirements - Part 11: Wireless LAN Medium
                       Access Control (MAC) and Physical Layer (PHY)
                       specifications", IEEE Standard 802.11, 2007,
                       <http://standards.ieee.org/getieee802/download/
                       802.11-2007.pdf>.

   [RFC5415]           Montemurro, M., Stanley, D., and P. Calhoun,
                       "CAPWAP Protocol Specification", RFC 5415, March
                       2009.

   [IEEE.802-1X.2004]  "Information technology - Telecommunications and
                       information exchange between systems - Local and
                       metropolitan area networks - Specific
                       requirements - Port-Based Network Access
                       Control", IEEE Standard 802.1X, 2004, <http://
                       standards.ieee.org/getieee802/download/
                       802.1X-2004.pdf>.








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   [IEEE.802-1Q.2005]  "Information technology - Telecommunications and
                       information exchange between systems - Local and
                       metropolitan area networks - Specific
                       requirements - Virtual Bridged Local Area
                       Networks", IEEE Standard 802.1Q, 2005, <http://
                       standards.ieee.org/getieee802/download/
                       802.1Q-2005.pdf>.

12.2.  Informative References

   [RFC4017]           Stanley, D., Walker, J., and B. Aboba,
                       "Extensible Authentication Protocol (EAP) Method
                       Requirements for Wireless LANs", RFC 4017,
                       March 2005.

   [RFC4118]           Yang, L., Zerfos, P., and E. Sadot, "Architecture
                       Taxonomy for Control and Provisioning of Wireless
                       Access Points (CAPWAP)", RFC 4118, June 2005.

   [RFC5418]           Kelly, S. and C. Clancy, "Control And
                       Provisioning for Wireless Access Points (CAPWAP)
                       Threat Analysis for IEEE 802.11 Deployments",
                       RFC 5418, March 2009.

   [WPA]               "Deploying Wi-Fi Protected Access (WPA) and WPA2
                       in the Enterprise", March 2005, <www.wi-fi.org>.

   [WMM]               "Support for Multimedia Applications with Quality
                       of Service in WiFi Networks)", September 2004,
                       <www.wi-fi.org>.





















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Editors' Addresses

   Pat R. Calhoun (editor)
   Cisco Systems, Inc.
   170 West Tasman Drive
   San Jose, CA  95134

   Phone: +1 408-902-3240
   EMail: pcalhoun@cisco.com


   Michael P. Montemurro (editor)
   Research In Motion
   5090 Commerce Blvd
   Mississauga, ON  L4W 5M4
   Canada

   Phone: +1 905-629-4746 x4999
   EMail: mmontemurro@rim.com


   Dorothy Stanley (editor)
   Aruba Networks
   1322 Crossman Ave
   Sunnyvale, CA  94089

   Phone: +1 630-363-1389
   EMail: dstanley@arubanetworks.com























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