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diff --git a/doc/rfc/rfc6153.txt b/doc/rfc/rfc6153.txt new file mode 100644 index 0000000..8b722f9 --- /dev/null +++ b/doc/rfc/rfc6153.txt @@ -0,0 +1,395 @@ + + + + + + +Internet Engineering Task Force (IETF) S. Das +Request for Comments: 6153 Telcordia Technologies +Category: Standards Track G. Bajko +ISSN: 2070-1721 Nokia + February 2011 + + + DHCPv4 and DHCPv6 Options for + Access Network Discovery and Selection Function (ANDSF) Discovery + +Abstract + + This document defines new Dynamic Host Configuration Protocol (DHCPv4 + and DHCPv6) options to enable a mobile node to discover Access + Network Discovery and Selection Function (ANDSF) entities in an IP + network. ANDSF is being developed in the Third Generation + Partnership Project (3GPP) and provides inter-system mobility + policies and access-network-specific information to the mobile nodes + (MNs). + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 5741. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc6153. + +Copyright Notice + + Copyright (c) 2011 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 + (http://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + + + +Das & Bajko Standards Track [Page 1] + +RFC 6153 ANDSF DHCP Options February 2011 + + +Table of Contents + + 1. Introduction ....................................................2 + 1.1. Conventions Used in This Document ..........................3 + 1.2. Terminology and Abbreviations Used in This Document ........3 + 2. ANDSF IPv4 Address Option for DHCPv4 ............................3 + 3. ANDSF IPv6 Address Option for DHCPv6 ............................4 + 4. Option Usage ....................................................4 + 4.1. Usage of ANDSF Options for DHCPv4 ..........................4 + 4.1.1. Mobile Node Behavior ................................4 + 4.2. Usage of ANDSF Options for DHCPv6 ..........................5 + 4.2.1. Mobile Node Behavior ................................5 + 5. Security Considerations .........................................5 + 6. IANA Considerations .............................................5 + 7. Acknowledgments .................................................6 + 8. References ......................................................6 + 8.1. Normative References .......................................6 + 8.2. Informative References .....................................6 + +1. Introduction + + Access Network Discovery and Selection Function (ANDSF) is being + defined in 3GPP [3GPPTS23.402] to provide necessary network discovery + and selection assistance data to the mobile nodes for multi-access + network scenarios where 3GPP access-network level solutions are not + sufficient for the mobile nodes to perform network discovery and + selection of non-3GPP networks. + + The information provided by ANDSF contains inter-system mobility + policies and access-network-specific data to assist the mobile node + with performing the inter-system handover. This set of information + can either be provisioned in the mobile node by the home operator or + provided to the mobile node (MN) dynamically by the ANDSF over the + S14 reference point as defined in [3GPPTS23.402] and [3GPPTS24.302]. + + In 3GPP, the ANDSF is located either in the subscriber's home + operator or visited network and needs to be known to the MN or + discovered by the MN. According to [3GPPTS23.402] and + [3GPPTS24.302], the ANDSF is discovered through interaction with the + Domain Name Service function or the DHCP server function. + + This document defines new DHCPv4 and DHCPv6 options called the ANDSF + IP Address Options, which allow the MN to locate an ANDSF server. + + + + + + + + +Das & Bajko Standards Track [Page 2] + +RFC 6153 ANDSF DHCP Options February 2011 + + +1.1. 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 [RFC2119]. + +1.2. Terminology and Abbreviations Used in This Document + + ANDSF (Access Network Discovery and Selection Function): An entity + that provides network discovery and selection assistance data to the + user entity (UE) as per operator policy [3GPPTS23.402]. + + Access Network: A network that is accessed by the UE. + + 3GPP Network: A radio access network specified by Third Generation + Partnership Project + + Non-3GPP Network: A radio access network specified outside 3GPP by + other projects or standards organizations + +2. ANDSF IPv4 Address Option for DHCPv4 + + This section describes the ANDSF IPv4 Address Option for DHCPv4. The + option layout is depicted below: + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Option Code | Length | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | IP Address | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + . . + +---------------------------------------------------------------+ + + Option Code + OPTION-IPv4_Address-ANDSF (142) + + Length + Length (in bytes) of the option excluding the 'Option Code' and + the 'Length' fields; 'Length' field is set to 4N, where N is the + number of IPv4 addresses carried in the option + + IP Address + IPv4 address(es) of ANDSF server(s) + + ANDSF servers MUST be listed in order of preference, and the client + SHOULD process them in decreasing order of preference. + + + + +Das & Bajko Standards Track [Page 3] + +RFC 6153 ANDSF DHCP Options February 2011 + + +3. ANDSF IPv6 Address Option for DHCPv6 + + This section describes the ANDSF IPv6 Address Option for DHCPv6. All + values in the option are represented in network byte order. The + option layout is depicted below: + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Option Code | Length | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | IP Address | + . . + +---------------------------------------------------------------+ + + Option Code + OPTION-IPv6_Address-ANDSF (143) + + Length + Length (in bytes) of the option excluding the 'Option Code' and + the 'Length' fields; 'Length' field is set to 16N, where N is the + number of IPv6 addresses carried in the option + + IP Address + IPv6 address(es) of ANDSF server(s) + + ANDSF servers MUST be listed in order of preference, and the client + SHOULD process them in decreasing order of preference. + +4. Option Usage + +4.1. Usage of ANDSF Options for DHCPv4 + + The requesting and sending of the proposed DHCPv4 options follow the + rules for DHCP options in [RFC2131]. + +4.1.1. Mobile Node Behavior + + The mobile node MAY request the IP address of an ANDSF server either + during initial association with a network or when the policy and + access network information is required from ANDSF. It MAY also + request the IP address of an ANDSF server when the network + information is outdated or the mobile node does not have any ANDSF + information. + + In order to request an address of a ANDSF server, the mobile node + (DHCP client) MUST include an ANDSF IPv4 Address Option in the + Parameter Request List (PRL) in the respective DHCP messages as + + + + +Das & Bajko Standards Track [Page 4] + +RFC 6153 ANDSF DHCP Options February 2011 + + + defined in [RFC2131] and [RFC2132]. The DHCP client MAY initiate a + new DHCP exchange or piggyback on other DHCP message exchanges. DHCP + client-handling PRL options are specified in [RFC2131], Section 4.4. + +4.2. Usage of ANDSF Options for DHCPv6 + + The requesting and sending of the proposed DHCPv6 options follow the + rules for DHCP options in [RFC3315]. + +4.2.1. Mobile Node Behavior + + The mobile node MAY request the IP address of an ANDSF server + according to the scenarios described in Section 4.1.1. + + In order to discover the address of an ANDSF server, the mobile node + (DHCP client) MUST include an ANDSF IPv6 Address Option in the Option + Request Option (ORO) in the respective DHCP messages as defined in + [RFC3315]. The DHCP client MAY initiate a new DHCP exchange or + piggyback on other DHCP message exchanges. DHCP client-handling ORO + options are specified in [RFC3315], Sections 17.1 and 18.1. + +5. Security Considerations + + If an adversary manages to modify the response from a DHCP server or + insert its own response, an MN could be led to contact a rogue ANDSF + server. A modified response could also be used to mount an + amplification attack. + + The DHCP authentication option described in [RFC3118] and [RFC3315] + MAY be used to mitigate the above attacks. In deployments where DHCP + authentication is not available, 3GPP-specific lower-layer security + services can be used to protect DHCP messages [3GPPTS33.402]. The + 3GPP ANDSF framework also provides additional mechanisms that can be + used to mitigate the above attacks and to protect message exchanges + between an ANDSF client and server at the higher layer + [3GPPTS33.402]. + +6. IANA Considerations + + This document defines two new DHCP options as described in Sections 2 + and 3: + + ANDSF IPv4 Address Option for DHCPv4 (OPTION-IPv4_Address-ANDSF) 142 + + ANDSF IPv6 Address Option for DHCPv6 (OPTION-IPv6_Address-ANDSF) 143 + + + + + + +Das & Bajko Standards Track [Page 5] + +RFC 6153 ANDSF DHCP Options February 2011 + + +7. Acknowledgments + + The authors would like to acknowledge the following individuals for + their valuable comments: Patrick Stuper, Vijay Devarapalli, Jouni + Korhonen, Jari Arkko, Ted Lemon, and Ralph Droms. + +8. References + +8.1. Normative References + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC + 2131, March 1997. + + [RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP + Vendor Extensions", RFC 2132, March 1997. + + [RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., + Perkins, C., and M. Carney, "Dynamic Host + Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, + July 2003. + + [RFC3118] Droms, R., Ed., and W. Arbaugh, Ed., "Authentication + for DHCP Messages", RFC 3118, June 2001. + +8.2. Informative References + + [3GPPTS23.402] 3GPP TS 23.402, v8.8.0 (2009-12): Architecture + enhancements for non-3GPP accesses, + http://www.3gpp.org/ftp/Specs/html-info/23402.htm. + + [3GPPTS24.302] 3GPP TS 24.302, v8.4.1 (2009-12): Access to the 3GPP + Evolved Packet Core (EPC) via non-3GPP access + networks; Stage 3, http://www.3gpp.org/ftp/Specs/html- + info/24302.htm. + + [3GPPTS33.402] 3GPP TS 33.402, v8.6.0 (2009-12): 3GPP System + Architecture Evolution (SAE); Security aspects of + non-3GPP accesses, http://www.3gpp.org/ftp/Specs/html- + info/33402.htm. + + + + + + + + + +Das & Bajko Standards Track [Page 6] + +RFC 6153 ANDSF DHCP Options February 2011 + + +Authors' Addresses + + Subir Das + Telcordia Technologies Inc. + EMail: subir@research.telcordia.com + + + Gabor Bajko + Nokia + EMail: gabor@bajko.nokia.com + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Das & Bajko Standards Track [Page 7] + |