path: root/doc/rfc/rfc2496.txt

Network Working Group                                    D. Fowler, Editor
Request for Comments: 2496                              Newbridge Networks
Obsoletes: 1407                                               January 1999
Category: Standards Track


      Definitions of Managed Objects for the DS3/E3 Interface Type

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) The Internet Society (1999).  All Rights Reserved.

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it describes objects used for managing DS3 and E3
   interfaces.  This document is a companion document with Definitions
   of Managed Objects for the DS0 (RFC 2494 [25]), DS1/E1/DS2/E2 (RFC
   2495 [17]), and the work in progress SONET/SDH Interface Types.

   This memo specifies a MIB module in a manner that is both compliant
   to the SNMPv2 SMI, and semantically identical to the peer SNMPv1
   definitions.

Table of Contents

   1 The SNMP Management Framework ................................  2
   1.1 Changes from RFC1407 .......................................  3
   2 Overview .....................................................  4
   2.1 Use of ifTable for DS3 Layer ...............................  5
   2.2 Usage Guidelines ...........................................  5
   2.2.1 Usage of ifStackTable ....................................  5
   2.2.2 Usage of Channelization for DS3, DS1, DS0 ................  7
   2.2.3 Usage of Channelization for DS3, DS2, DS1 ................  7
   2.2.4 Usage of Loopbacks .......................................  8
   2.3 Objectives of this MIB Module ..............................  9
   2.4 DS3/E3 Terminology .........................................  9
   2.4.1 Error Events ............................................. 10
   2.4.2 Performance Parameters ................................... 10



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   2.4.3 Performance Defects ...................................... 13
   2.4.4 Other Terms .............................................. 15
   3 Object Definitions ........................................... 15
   3.1 The DS3/E3 Near End Group .................................. 16
   3.1.1 The DS3/E3 Configuration Table ........................... 16
   3.1.2 The DS3/E3 Current Table ................................. 25
   3.1.3 The DS3/E3 Interval Table ................................ 28
   3.1.4 The DS3/E3 Total ......................................... 31
   3.2 The DS3 Far End Group ...................................... 34
   3.2.1 The DS3 Far End Configuration ............................ 35
   3.2.2 The DS3 Far End Current .................................. 37
   3.2.3 The DS3 Far End Interval Table ........................... 39
   3.2.4 The DS3 Far End Total .................................... 41
   3.3 The DS3/E3 Fractional Table ................................ 43
   3.4 The DS3 Trap Group ......................................... 46
   3.5 Conformance Groups ......................................... 46
   4 Appendix A - Use of dsx3IfIndex and dsx3LineIndex ............ 51
   5 Appendix B - The delay approach to Unavialable Seconds.  ..... 54
   6 Intellectual Property ........................................ 56
   7 Acknowledgments .............................................. 56
   8 References ................................................... 56
   9 Security Considerations ...................................... 58
   10 Author's Address ............................................ 59
   11 Full Copyright Statement .................................... 60

1.  The SNMP Management Framework

   The SNMP Management Framework presently consists of five major
   components:

    o   An overall architecture, described in RFC 2271 [1].

    o   Mechanisms for describing and naming objects and events for the
        purpose of management. The first version of this Structure of
        Management Information (SMI) is called SMIv1 and described in
        STD 16, RFC 1155 [2], STD 16, RFC 1212 [3] and RFC 1215 [4]. The
        second version, called SMIv2, is described in RFC 1902 [5], RFC
        1903 [6] and RFC 1904 [7].

    o   Message protocols for transferring management information. The
        first version of the SNMP message protocol is called SNMPv1 and
        described in STD 15, RFC 1157 [8]. A second version of the SNMP
        message protocol, which is not an Internet standards track
        protocol, is called SNMPv2c and described in RFC 1901 [9] and
        RFC 1906 [10].  The third version of the message protocol is
        called SNMPv3 and described in RFC 1906 [10], RFC 2272 [11] and
        RFC 2274 [12].




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    o   Protocol operations for accessing management information. The
        first set of protocol operations and associated PDU formats is
        described in STD 15, RFC 1157 [8]. A second set of protocol
        operations and associated PDU formats is described in RFC 1905
        [13].

    o   A set of fundamental applications described in RFC 2273 [14] and
        the view-based access control mechanism described in RFC 2275
        [15].  Managed objects are accessed via a virtual information
        store, termed the Management Information Base or MIB.  Objects
        in the MIB are defined using the mechanisms defined in the SMI.
        This memo specifies a MIB module that is compliant to the SMIv2.
        A MIB conforming to the SMIv1 can be produced through the
        appropriate translations. The resulting translated MIB must be
        semantically equivalent, except where objects or events are
        omitted because no translation is possible (use of Counter64).

        Some machine readable information in SMIv2 will be converted
        into textual descriptions in SMIv1 during the translation
        process. However, this loss of machine readable information is
        not considered to change the semantics of the MIB.

1.1.  Changes from RFC1407

   This MIB obsoletes RFC1407.  The changes from RFC1407 are the
   following:

        (1)  The Fractional Table has been deprecated

        (2)  This document uses SMIv2

        (3)  Values are given for ifTable and ifXTable

        (4)  Example usage of ifStackTable is included

        (5)  dsx3IfIndex has been deprecated

        (6)  The definition of valid intervals has been clarified
             for the case where the agent proxied for other devices.  In
             particular, the treatment of missing intervals has been
             clarified.

        (7)  An inward loopback has been added.

        (8)  Additional lineStatus bits have been added for Near End
             in Unavailable Signal State, Carrier Equipment Out of
             Service, DS@ Payload AIS, and DS@ Performance Threshold




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        (9)  A read-write line Length object has been added.

        (10) Added a lineStatus last change, trap and enabler.

        (11) Textual Conventions for statistics objects have
             been used.

        (12) A new object, dsx3LoopbackStatus, has been introduced to
             reflect the loopbacks established on a DS3/E3 interface and
             the source to the requests.  dsx3LoopbackConfig continues
             to be the desired loopback state while dsx3LoopbackStatus
             reflects the actual state.

        (13) A dual loopback has been added to allow the setting of an
             inward loopback and a line loopback at the same time.

        (14) An object has been added to indicated whether or not this
             is a channelized DS3/E3.

        (15) A new object has been added to indicate which DS1 is to set
             for remote loopback.

2.  Overview

   These objects are used when the particular media being used to
   realize an interface is a DS3/E3 interface.  At present, this applies
   to these values of the ifType variable in the Internet-standard MIB:

        ds3 (30)

   The DS3 definitions contained herein are based on the DS3
   specifications in ANSI T1.102-1987, ANSI T1.107-1988, ANSI T1.107a-
   1990, and ANSI T1.404-1989 [8,9,9a,10].  The E3 definitions contained
   herein are based on the E3 specifications in CCITT G.751 [12].

















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2.1.  Use of ifTable for DS3 Layer

   Only the ifGeneralGroup needs to be supported.

           ifTable Object    Use for DS3 Layer
======================================================================
           ifIndex           Interface index.

           ifDescr           See interfaces MIB [5]

           ifType            ds3(30)

           ifSpeed           Speed of line rate
                             DS3 - 44736000
                             E3  - 34368000

           ifPhysAddress     The value of the Circuit Identifier.
                             If no Circuit Identifier has been assigned
                             this object should have an octet string
                             with zero length.

           ifAdminStatus     See interfaces MIB [5]

           ifOperStatus      See interfaces MIB [5]

           ifLastChange      See interfaces MIB [5]

           ifName            See interfaces MIB [5]

           ifLinkUpDownTrapEnable   Set to enabled(1).

           ifHighSpeed       Speed of line in Mega-bits per second
                             (either 45 or 34)

           ifConnectorPresent Set to true(1) normally, except for
                              cases such as DS3/E3 over AAL1/ATM where
                              false(2) is appropriate

2.2.  Usage Guidelines

2.2.1.  Usage of ifStackTable

   The assignment of the index values could for example be:

           ifIndex  Description
           1        Ethernet
           2        Line#A Router
           3        Line#B Router



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           4        Line#C Router
           5        Line#D Router
           6        Line#A CSU Router
           7        Line#B CSU Router
           8        Line#C CSU Router
           9        Line#D CSU Router
           10       Line#A CSU Network
           11       Line#B CSU Network
           12       Line#C CSU Network
           13       Line#D CSU Network

   The ifStackTable is then used to show the relationships between the
   various DS3 interfaces.

           ifStackTable Entries

           HigherLayer   LowerLayer
           2             6
           3             7
           4             8
           5             9
           6             10
           7             11
           8             12
           9             13

   If the CSU shelf is managed by itself by a local SNMP Agent, the
   situation would be identical, except the Ethernet and the 4 router
   interfaces are deleted.  Interfaces would also be numbered from 1 to
   8.

           ifIndex  Description
           1        Line#A CSU Router
           2        Line#B CSU Router
           3        Line#C CSU Router
           4        Line#D CSU Router
           5        Line#A CSU Network
           6        Line#B CSU Network
           7        Line#C CSU Network
           8        Line#D CSU Network

           ifStackTable Entries

           HigherLayer   LowerLayer
           1             5
           2             6
           3             7
           4             8



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2.2.2.  Usage of Channelization for DS3, DS1, DS0

   An example is given here to explain the channelization objects in the
   DS3, DS1, and DS0 MIBs to help the implementor use the objects
   correctly. Treatment of E3 and E1 would be similar, with the number
   of DS0s being different depending on the framing of the E1.

   Assume that a DS3 (with ifIndex 1) is Channelized into DS1s (without
   DS2s).  The object dsx3Channelization is set to enabledDs1.  When
   this object is set to enabledDS1, 28 ifEntries of type DS1 will be
   created by the agent. If dsx3Channelization is set to disabled, then
   the DS1s are destroyed.

   Assume the entries in the ifTable for the DS1s are created in channel
   order and the ifIndex values are 2 through 29. In the DS1 MIB, there
   will be an entry in the dsx1ChanMappingTable for each ds1.  The
   entries will be as follows:

        dsx1ChanMappingTable Entries

        ifIndex  dsx1Ds1ChannelNumber   dsx1ChanMappedIfIndex

        1        1                      2
        1        2                      3
        ......
        1        28                     29

   In addition, the DS1s are channelized into DS0s.  The object
   dsx1Channelization is set to enabledDS0 for each DS1.  There will be
   24 DS0s in the ifTable for each DS1.  Assume the entries in the
   ifTable are created in channel order and the ifIndex values for the
   DS0s in the first DS1 are 30 through 53.  In the DS0 MIB, there will
   be an entry in the dsx0ChanMappingTable for each DS0.  The entries
   will be as follows:

        dsx0ChanMappingTable Entries

        ifIndex   dsx0Ds0ChannelNumber  dsx0ChanMappedIfIndex
        2         1                     30
        2         2                     31
        ......
        2         24                    53

2.2.3.  Usage of Channelization for DS3, DS2, DS1

   An example is given here to explain the channelization objects in the
   DS3 and DS1 MIBs to help the implementor use the objects correctly.




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   Assume that a DS3 (with ifIndex 1) is Channelized into DS2s.  The
   object dsx3Channelization is set to enabledDs2.  There will be 7 DS2s
   (ifType of DS1) in the ifTable.  Assume the entries in the ifTable
   for the DS2s are created in channel order and the ifIndex values are
   2 through 8. In the DS1 MIB, there will be an entry in the
   dsx1ChanMappingTable for each DS2.  The entries will be as follows:

        dsx1ChanMappingTable Entries

        ifIndex  dsx1Ds1ChannelNumber   dsx1ChanMappedIfIndex
        1        1                      2
        1        2                      3
        ......
        1        7                      8

   In addition, the DS2s are channelized into DS1s.  The object
   dsx1Channelization is set to enabledDS1 for each DS2.  There will be
   4 DS1s in the ifTable for each DS2.  Assume the entries in the
   ifTable are created in channel order and the ifIndex values for the
   DS1s in the first DS2 are 9 through 12, then 13 through 16 for the
   second DS2, and so on.  In the DS1 MIB, there will be an entry in the
   dsx1ChanMappingTable for each DS1.  The entries will be as follows:

        dsx1ChanMappingTable Entries

        ifIndex   dsx1Ds1ChannelNumber  dsx1ChanMappedIfIndex
        2         1                     9
        2         2                     10
        2         3                     11
        2         4                     12
        3         1                     13
        3         2                     14
        ...
        8         4                     36

2.2.4.  Usage of Loopbacks

   This section discusses the behaviour of objects related to loopbacks.

   The object dsx3LoopbackConfig represents the desired state of
   loopbacks on this interface.  Using this object a Manager can
   request:
       LineLoopback
       PayloadLoopback (if ESF framing)
       InwardLoopback
       DualLoopback (Line + Inward)
       NoLoopback




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   The remote end can also request lookbacks either through the FDL
   channel if ESF or inband if D4.  The loopbacks that can be request
   this way are:
   LineLoopback
   PayloadLoopback (if ESF framing)
   NoLoopback

   To model the current state of loopbacks on a DS3 interface, the
   object dsx3LoopbackStatus defines which loopback is currently applies
   to an interface.  This objects, which is a bitmap, will have bits
   turned on which reflect the currently active loopbacks on the
   interface as well as the source of those loopbacks.

   The following restrictions/rules apply to loopbacks:

   The far end cannot undo loopbacks set by a manager.

   A manager can undo loopbacks set by the far end.

   Both a line loopback and an inward loopback can be set at the same
   time.  Only these two loopbacks can co-exist and either one may be
   set by the manager or the far end.  A LineLoopback request from the
   far end is incremental to an existing Inward loopback established by
   a manager.  When a NoLoopback is received from the far end in this
   case, the InwardLoopback remains in place.

2.3.  Objectives of this MIB Module

   There are numerous things that could be included in a MIB for DS3/E3
   signals:  the management of multiplexors, CSUs, DSUs, and the like.
   The intent of this document is to facilitate the common management of
   all devices with DS3/E3 interfaces.  As such, a design decision was
   made up front to very closely align the MIB with the set of objects
   that can generally be read from DS3/E3 devices that are currently
   deployed.

2.4.  DS3/E3 Terminology

   The terminology used in this document to describe error conditions on
   a DS3 interface as monitored by a DS3 device are based on the late
   but not final draft of what became the ANSI T1.231 standard [11].  If
   the definition in this document does not match the definition in the
   ANSI T1.231 document, the implementer should follow the definition
   described in this document.







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2.4.1.  Error Events

     Bipolar Violation (BPV) Error Event
          A bipolar violation error event, for B3ZS(HDB3)-coded signals,
          is the occurrence of a pulse of the same polarity as the
          previous pulse without being part of the zero substitution
          code, B3ZS(HDB3).  For B3ZS(HDB3)-coded signals, a bipolar
          violation error event may also include other error patterns
          such as:  three(four) or more consecutive zeros and incorrect
          polarity. (See T1.231 section 7.1.1.1.1)

     Excessive Zeros (EXZ) Error Event
          An EXZ is the occurrence of any zero string length equal to or
          greater than 3 for B3ZS, or greater than 4 for HDB3.  (See
          T1.231 section 7.1.1.1.2)

     Line Coding Violation (LCV) Error Event
          This parameter is a count of both BPVs and EXZs occurring over
          the accumulation period.  An EXZ increments the LCV by one
          regardless of the length of the zero string. (Also known as
          CV-L.  See T1.231 section 7.4.1.1)

     P-bit Coding Violation (PCV) Error Event
          For all DS3 applications, a coding violation error event is a
          P-bit Parity Error event.  A P-bit Parity Error event is the
          occurrence of a received P-bit code on the DS3 M-frame that is
          not identical to the corresponding locally- calculated code.
          (See T1.231 section 7.1.1.2.1)

     C-bit Coding Violation (CCV) Error Event
          For C-bit Parity and SYNTRAN DS3 applications, this is the
          count of coding violations reported via the C-bits.  For C-bit
          Parity, it is a count of CP-bit parity errors occurring in the
          accumulation interval.  For SYNTRAN, it is a count of CRC-9
          errors occurring in the accumulation interval. (See T1.231
          section 7.1.1.2.2)

2.4.2.  Performance Parameters

   All performance parameters are accumulated in fifteen minute
   intervals and up to 96 intervals (24 hours worth) are kept by an
   agent.  Fewer than 96 intervals of data will be available if the
   agent has been restarted within the last 24 hours.  In addition,
   there is a rolling 24-hour total of each performance parameter.







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   There is no requirement for an agent to ensure fixed relationship
   between the start of a fifteen minute interval and any wall clock;
   however some agents may align the fifteen minute intervals with
   quarter hours.

   Performance parameters are of types PerfCurrentCount,
   PerfIntervalCount and PerfTotalCount.  These textual conventions are
   all Gauge32, and they are used because it is possible for these
   objects to decrease.  Objects may decrease when Unavailable Seconds
   occurs across a fifteen minutes interval boundary. See Unavailable
   Seconds discussion later in this section.

     Line Errored Seconds (LES)
          A Line Errored Second is a second in which one or more CV
          occurred OR one or more LOS defects.  (Also known as ES-L. See
          T1.231 section 7.4.1.2)

     P-bit Errored Seconds (PES)
          An PES is a second with one or more PCVs OR one or more Out of
          Frame defects OR a detected incoming AIS. This gauge is not
          incremented when UASs are counted.  (Also known as ESP-P. See
          T1.231 section 7.4.2.2)

     P-bit Severely Errored Seconds (PSES)
          A PSES is a second with 44 or more PCVs OR one or more Out of
          Frame defects OR a detected incoming AIS. This gauge is not
          incremented when UASs are counted.  (Also known as SESP-P. See
          T1.231 section 7.4.2.5)

     C-bit Errored Seconds (CES)
          An CES is a second with one or more CCVs OR one or more Out of
          Frame defects OR a detected incoming AIS.  This count is only
          for the SYNTRAN and C-bit Parity DS3 applications. This gauge
          is not incremented when UASs are counted. (Also known as
          ESCP-P. See T1.231 section 7.4.2.2)

     C-bit Severely Errored Seconds (CSES)
          A CSES is a second with 44 or more CCVs OR one or more Out of
          Frame defects OR a detected incoming AIS.  This count is only
          for the SYNTRAN and C-bit Parity DS3 applications.  This gauge
          is not incremented when UASs are counted. (Also known as
          SESCP-P. See T1.231 section 7.4.2.5)

     Severely Errored Framing Seconds (SEFS)
          A SEFS is a second with one or more Out of Frame defects OR a
          detected incoming AIS. This item is not incremented during
          unavailable seconds.  (Also known as SAS-P. See T1.231 section
          7.4.2.6)



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     Unavailable Seconds (UAS)
          UAS are calculated by counting the number of seconds that the
          interface is unavailable.  The DS3 interface is said to be
          unavailable from the onset of 10 contiguous PSESs, or the
          onset of the condition leading to a failure (see Failure
          States).  If the condition leading to the failure was
          immediately preceded by one or more contiguous PSESs, then the
          DS3 interface unavailability starts from the onset of these
          PSESs.  Once unavailable, and if no failure is present, the
          DS3 interface becomes available at the onset of 10 contiguous
          seconds with no PSESs.  Once unavailable, and if a failure is
          present, the DS3 interface becomes available at the onset of
          10 contiguous seconds with no PSESs, if the failure clearing
          time is less than or equal to 10 seconds.  If the failure
          clearing time is more than 10 seconds, the DS3 interface
          becomes available at the onset of 10 contiguous seconds with
          no PSESs, or the onset period leading to the successful
          clearing condition, whichever occurs later. With respect to
          the DS3 error counts, all counters are incremented while the
          DS3 interface is deemed available.  While the interface is
          deemed unavailable, the only count that is incremented is
          UASs.

          Note that this definition implies that the agent cannot
          determine until after a ten second interval has passed whether
          a given one-second interval belongs to available or
          unavailable time.  If the agent chooses to update the various
          performance statistics in real time then it must be prepared
          to retroactively reduce the PES, PSES, CES, and CSES counts by
          10 and increase the UAS count by 10 when it determines that
          available time has been entered.  It must also be prepared to
          adjust the PCV, CCV, and SEFS count as necessary since these
          parameters are not accumulated during unavailable time.  It
          must be similarly prepared to retroactively decrease the UAS
          count by 10 and increase the PES, CES, PCV, and CCV counts as
          necessary upon entering available time.  A special case exists
          when the 10 second period leading to available or unavailable
          time crosses a 900 second statistics window boundary, as the
          foregoing description implies that the PCV, CCV, PES, CES,
          PSES, CSEC, SEFS, and UAS counts for the PREVIOUS interval
          must be adjusted.  In this case successive GETs of the
          affected dsx3IntervalPSESs and dsx3IntervalUASs objects will
          return differing values if the first GET occurs during the
          first few seconds of the window.







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          The agent may instead choose to delay updates to the various
          statistics by 10 seconds in order to avoid retroactive
          adjustments to the counters.  A way to do this is sketched in
          Appendix B.

          In any case, a linkDown trap shall be sent only after the
          agent has determined for certain that the unavailable state
          has been entered, but the time on the trap will be that of the
          first UAS (i.e., 10 seconds earlier).  A linkUp trap shall be
          handled similarly.

          According to ANSI T1.231 unavailable time begins at the
          _onset_ of 10 contiguous severely errored seconds -- that is,
          unavailable time starts with the _first_ of the 10 contiguous
          SESs.  Also, while an interface is deemed unavailable all
          counters for that interface are frozen except for the UAS
          count.  It follows that an implementation which strictly
          complies with this standard must _not_ increment any counters
          other than the UAS count -- even temporarily -- as a result of
          anything that happens during those 10 seconds.  Since changes
          in the signal state lag the data to which they apply by 10
          seconds, an ANSI-compliant implementation must pass the the
          one-second statistics through a 10-second delay line prior to
          updating any counters.  That can be done by performing the
          following steps at the end of each one second interval.

   i)   Read near/far end CV counter and alarm status flags from the
        hardware.

   ii)  Accumulate the CV counts for the preceding second and compare
        them to the ES and SES threshold for the layer in question.
        Update the signal state and shift the one-second CV counts and
        ES/SES flags into the 10-element delay line.  Note that far-end
        one-second statistics are to be flagged as "absent" during any
        second in which there is an incoming defect at the layer in
        question or at any lower layer.

   iii) Update the current interval statistics using the signal state
        from the _previous_ update cycle and the one-second CV counts
        and ES/SES flags shifted out of the 10-element delay line.

   This approach is further described in Appendix B.

2.4.3.  Performance Defects

     Failure States:
          The Remote Alarm Indication (RAI) failure, in SYNTRAN
          applications, is declared after detecting the Yellow Alarm



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          Signal on the alarm channel.  See ANSI T1.107a-1990 [9a]. The
          Remote Alarm Indication failure, in C-bit Parity DS3
          applications, is declared as soon as the presence of either
          one or two alarm signals are detected on the Far End Alarm
          Channel.  See [9].  The Remote Alarm Indication failure may
          also be declared after detecting the far-end SEF/AIS defect
          (aka yellow).  The Remote Alarm Indication failure is cleared
          as soon as the presence of the any of the above alarms are
          removed.

          Also, the incoming failure state is declared when a defect
          persists for at least 2-10 seconds.  The defects are the
          following:  Loss of Signal (LOS), an Out of Frame (OOF) or an
          incoming Alarm Indication Signal (AIS).  The Failure State is
          cleared when the defect is absent for less than or equal to 20
          seconds.

     Far End SEF/AIS defect (aka yellow)
          A Far End SEF/AIS defect is the occurrence of the two X-bits
          in a M-frame set to zero.  The Far End SEF/AIS defect is
          terminated when the two X-bits in a M-frame are set to one.
          (Also known as SASCP-PFE. See T1.231 section 7.4.4.2.6)

     Out of Frame (OOF) defect
          A DS3 OOF defect is detected when any three or more errors in
          sixteen or fewer consecutive F-bits occur within a DS3 M-
          frame.  An OOF defect may also be called a Severely Errored
          Frame (SEF) defect.  An OOF defect is cleared when reframe
          occurs.  A DS3 Loss of Frame (LOF) failure is declared when
          the DS3 OOF defect is consistent for 2 to 10 seconds.  The DS3
          OOF defect ends when reframe occurs.  The DS3 LOF failure is
          cleared when the DS3 OOF defect is absent for 10 to 20
          seconds. (See T1.231 section 7.1.2.2.1)

          An E3 OOF defect is detected when four consecutive frame
          alignment signals have been incorrectly received in there
          predicted positions in an E3 signal. E3 frame alignment occurs
          when the presence of three consecutive frame alignment signals
          have been detected.

     Loss of Signal (LOS) defect
          The DS3 LOS defect is declared upon observing 175 +/- 75
          contiguous pulse positions with no pulses of either positive
          or negative polarity.  The DS3 LOS defect is terminated upon
          observing an average pulse density of at least 33% over a
          period of 175 +/- 75 contiguous pulse positions starting with
          the receipt of a pulse. (See T1.231 section 7.1.2.1.1)




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     Alarm Indication Signal (AIS) defect
          The DS3 AIS is framed with "stuck stuffing."  This implies
          that it has a valid M-subframe alignments bits, M-frame
          alignment bits, and P bits.  The information bits are set to a
          1010... sequence, starting with a one (1) after each M-
          subframe alignment bit, M-frame alignment bit, X bit, P bit,
          and C bit.  The C bits are all set to zero giving what is
          called "stuck stuffing."  The X bits are set to one. The DS3
          AIS defect is declared after DS3 AIS is present in contiguous
          M-frames for a time equal to or greater than T, where 0.2 ms
          <= T <= 100 ms.  The DS3 AIS defect is terminated after AIS is
          absent in contiguous M-frames for a time equal to or greater
          than T.  (See T1.231 section 7.1.2.2.3)

          The E3 binary content of the AIS is nominally a continuous
          stream of ones.  AIS detection and the application of
          consequent actions, should be completed within a time limit of
          1 ms.

2.4.4.  Other Terms

     Circuit Identifier
          This is a character string specified by the circuit vendor,
          and is useful when communicating with the vendor during the
          troubleshooting process.

     Proxy
          In this document, the word proxy is meant to indicate an
          application which receives SNMP messages and replies to them
          on behalf of the devices which implement the actual DS3/E3
          interfaces.  The proxy may have already collected the
          information about the DS3/E3 interfaces into its local
          database and may not necessarily forward the requests to the
          actual DS3/E3 interface.  It is expected in such an
          application that there are periods of time where the proxy is
          not communicating with the DS3/E3 interfaces.  In these
          instances the proxy will not necessarily have up-to-date
          configuration information and will most likely have missed the
          collection of some statistics data.  Missed statistics data
          collection will result in invalid data in the interval table.

3.  Object Definitions

     DS3-MIB DEFINITIONS ::= BEGIN

     IMPORTS
          MODULE-IDENTITY, OBJECT-TYPE,
          NOTIFICATION-TYPE, transmission         FROM SNMPv2-SMI



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          DisplayString, TimeStamp, TruthValue    FROM SNMPv2-TC
          MODULE-COMPLIANCE, OBJECT-GROUP,
          NOTIFICATION-GROUP                      FROM SNMPv2-CONF
          InterfaceIndex                          FROM IF-MIB
          PerfCurrentCount, PerfIntervalCount,
          PerfTotalCount                          FROM PerfHist-TC-MIB;


     ds3 MODULE-IDENTITY
         LAST-UPDATED "9808012130Z"
         ORGANIZATION "IETF Trunk MIB Working Group"
         CONTACT-INFO
           "        David Fowler

            Postal: Newbridge Networks Corporation
                    600 March Road
                    Kanata, Ontario, Canada K2K 2E6

                    Tel: +1 613 591 3600
                    Fax: +1 613 599 3667

            E-mail: davef@newbridge.com"
         DESCRIPTION
              "The is the MIB module that describes
               DS3 and E3 interfaces objects."

         ::= { transmission 30 }

     -- The DS3/E3 Near End Group

     -- The DS3/E3 Near End Group consists of four tables:
     --    DS3/E3 Configuration
     --    DS3/E3 Current
     --    DS3/E3 Interval
     --    DS3/E3 Total

     -- the DS3/E3 Configuration Table

     dsx3ConfigTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF Dsx3ConfigEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "The DS3/E3 Configuration table."
          ::= { ds3 5 }

     dsx3ConfigEntry OBJECT-TYPE
          SYNTAX  Dsx3ConfigEntry



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          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "An entry in the DS3/E3 Configuration table."
          INDEX   { dsx3LineIndex }
          ::= { dsx3ConfigTable 1 }

     Dsx3ConfigEntry ::=
          SEQUENCE {
              dsx3LineIndex                        InterfaceIndex,
              dsx3IfIndex                          InterfaceIndex,
              dsx3TimeElapsed                      INTEGER,
              dsx3ValidIntervals                   INTEGER,
              dsx3LineType                         INTEGER,
              dsx3LineCoding                       INTEGER,
              dsx3SendCode                         INTEGER,
              dsx3CircuitIdentifier                DisplayString,
              dsx3LoopbackConfig                   INTEGER,
              dsx3LineStatus                       INTEGER,
              dsx3TransmitClockSource              INTEGER,
              dsx3InvalidIntervals                 INTEGER,
              dsx3LineLength                       INTEGER,
              dsx3LineStatusLastChange             TimeStamp,
              dsx3LineStatusChangeTrapEnable       INTEGER,
              dsx3LoopbackStatus                   INTEGER,
              dsx3Channelization                   INTEGER,
              dsx3Ds1ForRemoteLoop                 INTEGER
     }

     dsx3LineIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "This object should be made equal to ifIndex.  The
                 next paragraph describes its previous usage.
                 Making the object equal to ifIndex allows propoer
                 use of ifStackTable.

                 Previously, this object was the identifier of a
                 DS3/E3 Interface on a managed device.  If there is
                 an ifEntry that is directly associated with this
                 and only this DS3/E3 interface, it should have the
                 same value as ifIndex.  Otherwise, number the
                 dsx3LineIndices with an unique identifier
                 following the rules of choosing a number that is
                 greater than ifNumber and numbering the inside
                 interfaces (e.g., equipment side) with even



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                 numbers and outside interfaces (e.g, network side)
                 with odd numbers."
          ::= { dsx3ConfigEntry 1 }

     dsx3IfIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  deprecated
          DESCRIPTION
                 "This value for this object is equal to the value
                 of ifIndex from the Interfaces table of MIB II
                 (RFC 1213)."
          ::= { dsx3ConfigEntry 2 }

     dsx3TimeElapsed OBJECT-TYPE
          SYNTAX  INTEGER (0..899)
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of seconds that have elapsed since the
                 beginning of the near end current error-
                 measurement period.  If, for some reason, such as
                 an adjustment in the system's time-of-day clock,
                 the current interval exceeds the maximum value,
                 the agent will return the maximum value."

          ::= { dsx3ConfigEntry 3 }

     dsx3ValidIntervals OBJECT-TYPE
          SYNTAX  INTEGER (0..96)
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of previous near end intervals for
                 which data was collected.  The value will be
                 96 unless the interface was brought online within
                 the last 24 hours, in which case the value will be
                 the number of complete 15 minute near end
                 intervals since the interface has been online.  In
                 the case where the agent is a proxy, it is
                 possible that some intervals are unavailable.  In
                 this case, this interval is the maximum interval
                 number for which data is available."
          ::= { dsx3ConfigEntry 4 }

     dsx3LineType OBJECT-TYPE
          SYNTAX  INTEGER {
                     dsx3other(1),



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                     dsx3M23(2),
                     dsx3SYNTRAN(3),
                     dsx3CbitParity(4),
                     dsx3ClearChannel(5),
                     e3other(6),
                     e3Framed(7),
                     e3Plcp(8)
                 }
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
                 "This variable indicates the variety of DS3 C-bit
                 or E3 application implementing this interface. The
                 type of interface affects the interpretation of
                 the usage and error statistics.  The rate of DS3
                 is 44.736 Mbps and E3 is 34.368 Mbps.  The
                 dsx3ClearChannel value means that the C-bits are
                 not used except for sending/receiving AIS.
                 The values, in sequence, describe:

                 TITLE:            SPECIFICATION:
                 dsx3M23            ANSI T1.107-1988 [9]
                 dsx3SYNTRAN        ANSI T1.107-1988 [9]
                 dsx3CbitParity     ANSI T1.107a-1990 [9a]
                 dsx3ClearChannel   ANSI T1.102-1987 [8]
                 e3Framed           CCITT G.751 [12]
                 e3Plcp             ETSI T/NA(91)18 [13]."
          ::= { dsx3ConfigEntry 5 }

     dsx3LineCoding OBJECT-TYPE
          SYNTAX  INTEGER {
                     dsx3Other(1),
                     dsx3B3ZS(2),
                     e3HDB3(3)
                 }
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
                 "This variable describes the variety of Zero Code
                 Suppression used on this interface, which in turn
                 affects a number of its characteristics.

                 dsx3B3ZS and e3HDB3 refer to the use of specified
                 patterns of normal bits and bipolar violations
                 which are used to replace sequences of zero bits
                 of a specified length."
          ::= { dsx3ConfigEntry 6 }




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     dsx3SendCode OBJECT-TYPE
          SYNTAX  INTEGER {
                    dsx3SendNoCode(1),
                    dsx3SendLineCode(2),
                    dsx3SendPayloadCode(3),
                    dsx3SendResetCode(4),
                    dsx3SendDS1LoopCode(5),
                    dsx3SendTestPattern(6)
                    }
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
                 "This variable indicates what type of code is
                 being sent across the DS3/E3 interface by the
                 device.  (These are optional for E3 interfaces.)
                 Setting this variable causes the interface to
                 begin sending the code requested.
                 The values mean:

                    dsx3SendNoCode
                        sending looped or normal data

                    dsx3SendLineCode
                        sending a request for a line loopback

                    dsx3SendPayloadCode
                        sending a request for a payload loopback
                        (i.e., all DS1/E1s in a DS3/E3 frame)

                    dsx3SendResetCode
                        sending a loopback deactivation request

                    dsx3SendDS1LoopCode
                        requesting to loopback a particular DS1/E1
                        within a DS3/E3 frame.  The DS1/E1 is
                        indicated in dsx3Ds1ForRemoteLoop.

                    dsx3SendTestPattern
                        sending a test pattern."
          ::= { dsx3ConfigEntry 7 }

     dsx3CircuitIdentifier OBJECT-TYPE
          SYNTAX  DisplayString (SIZE (0..255))
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
                 "This variable contains the transmission vendor's
                 circuit identifier, for the purpose of



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                 facilitating troubleshooting."
          ::= { dsx3ConfigEntry 8 }

     dsx3LoopbackConfig OBJECT-TYPE
          SYNTAX  INTEGER {
                      dsx3NoLoop(1),
                      dsx3PayloadLoop(2),
                      dsx3LineLoop(3),
                      dsx3OtherLoop(4),
                      dsx3InwardLoop(5),
                      dsx3DualLoop(6)
                    }
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
               "This variable represents the desired loopback
               configuration of the DS3/E3 interface.

               The values mean:

               dsx3NoLoop
                 Not in the loopback state.  A device that is
                 not capable of performing a loopback on
                 the interface shall always return this as
                 its value.

               dsx3PayloadLoop
                 The received signal at this interface is looped
                 through the device.  Typically the received signal
                 is looped back for retransmission after it has
                 passed through the device's framing function.

               dsx3LineLoop
                 The received signal at this interface does not
                 go through the device (minimum penetration) but
                 is looped back out.

               dsx3OtherLoop
                 Loopbacks that are not defined here.

               dsx3InwardLoop
                 The sent signal at this interface is looped back
                 through the device.

               dsx3DualLoop
                 Both dsx1LineLoop and dsx1InwardLoop will be
                 active simultaneously."
          ::= { dsx3ConfigEntry 9 }



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     dsx3LineStatus OBJECT-TYPE
          SYNTAX  INTEGER (1..4095)
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "This variable indicates the Line Status of the
                 interface.  It contains loopback state information
                 and failure state information.  The dsx3LineStatus
                 is a bit map represented as a sum, therefore, it
                 can represent multiple failures and a loopback
                 (see dsx3LoopbackConfig object for the type of
                 loopback) simultaneously.  The dsx3NoAlarm must be
                 set if and only if no other flag is set.

                 If the dsx3loopbackState bit is set, the loopback
                 in effect can be determined from the
                 dsx3loopbackConfig object.
       The various bit positions are:
        1     dsx3NoAlarm         No alarm present
        2     dsx3RcvRAIFailure   Receiving Yellow/Remote
                                  Alarm Indication
        4     dsx3XmitRAIAlarm    Transmitting Yellow/Remote
                                  Alarm Indication
        8     dsx3RcvAIS          Receiving AIS failure state
       16     dsx3XmitAIS         Transmitting AIS
       32     dsx3LOF             Receiving LOF failure state
       64     dsx3LOS             Receiving LOS failure state
      128     dsx3LoopbackState   Looping the received signal
      256     dsx3RcvTestCode     Receiving a Test Pattern
      512     dsx3OtherFailure    any line status not defined
                                  here
     1024     dsx3UnavailSigState Near End in Unavailable Signal
                                  State
     2048     dsx3NetEquipOOS     Carrier Equipment Out of Service"
     ::= { dsx3ConfigEntry 10 }

dsx3TransmitClockSource OBJECT-TYPE
     SYNTAX  INTEGER {
                loopTiming(1),
                localTiming(2),
                throughTiming(3)
            }
     MAX-ACCESS  read-write
     STATUS  current
     DESCRIPTION
            "The source of Transmit Clock.

            loopTiming indicates that the recovered receive clock



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            is used as the transmit clock.

            localTiming indicates that a local clock source is used
            or that an external clock is attached to the box
            containing the interface.

            throughTiming indicates that transmit clock is derived
            from the recovered receive clock of another DS3
            interface."
          ::= { dsx3ConfigEntry 11 }

     dsx3InvalidIntervals OBJECT-TYPE
          SYNTAX  INTEGER (0..96)
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                      "The number of intervals in the range from 0 to
                 dsx3ValidIntervals for which no data is
                 available.  This object will typically be zero
                 except in cases where the data for some intervals
                 are not available (e.g., in proxy situations)."
          ::= { dsx3ConfigEntry 12 }

     dsx3LineLength OBJECT-TYPE
          SYNTAX  INTEGER (0..64000)
          UNITS "meters"
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
                 "The length of the ds3 line in meters.  This
                 object provides information for line build out
                 circuitry if it exists and can use this object to
                 adjust the line build out."
          ::= { dsx3ConfigEntry 13 }

     dsx3LineStatusLastChange OBJECT-TYPE
          SYNTAX  TimeStamp
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The value of MIB II's sysUpTime object at the
                 time this DS3/E3 entered its current line status
                 state.  If the current state was entered prior to
                 the last re-initialization of the proxy-agent,
                 then this object contains a zero value."
          ::= { dsx3ConfigEntry 14 }

     dsx3LineStatusChangeTrapEnable  OBJECT-TYPE



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          SYNTAX      INTEGER {
                         enabled(1),
                         disabled(2)
                      }
          MAX-ACCESS  read-write
          STATUS      current
          DESCRIPTION
                 "Indicates whether dsx3LineStatusChange traps
                 should be generated for this interface."
          DEFVAL { disabled }
          ::= { dsx3ConfigEntry 15 }

     dsx3LoopbackStatus  OBJECT-TYPE
          SYNTAX      INTEGER (1..127)
          MAX-ACCESS  read-only
          STATUS      current
          DESCRIPTION
                 "This variable represents the current state of the
                 loopback on the DS3 interface.  It contains
                 information about loopbacks established by a
                 manager and remotely from the far end.

                 The dsx3LoopbackStatus is a bit map represented as
                 a sum, therefore is can represent multiple
                 loopbacks simultaneously.

                 The various bit positions are:
                  1  dsx3NoLoopback
                  2  dsx3NearEndPayloadLoopback
                  4  dsx3NearEndLineLoopback
                  8  dsx3NearEndOtherLoopback
                 16  dsx3NearEndInwardLoopback
                 32  dsx3FarEndPayloadLoopback
                 64  dsx3FarEndLineLoopback"

     ::= { dsx3ConfigEntry 16 }

     dsx3Channelization  OBJECT-TYPE
          SYNTAX      INTEGER {
                         disabled(1),
                         enabledDs1(2),
                         enabledDs2(3)
                      }
          MAX-ACCESS  read-write
          STATUS      current
          DESCRIPTION
                 "Indicates whether this ds3/e3 is channelized or
                 unchannelized.  The value of enabledDs1 indicates



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                 that this is a DS3 channelized into DS1s.  The
                 value of enabledDs3 indicated that this is a DS3
                 channelized into DS2s.  Setting this object will
                 cause the creation or deletion of DS2 or DS1
                 entries in the ifTable.  "
     ::= { dsx3ConfigEntry 17 }

     dsx3Ds1ForRemoteLoop  OBJECT-TYPE
          SYNTAX      INTEGER (0..29)

          MAX-ACCESS  read-write
          STATUS      current
          DESCRIPTION
                 "Indicates which ds1/e1 on this ds3/e3 will be
                 indicated in the remote ds1 loopback request.  A
                 value of 0 means no DS1 will be looped.  A value
                 of 29 means all ds1s/e1s will be looped."
     ::= { dsx3ConfigEntry 18 }


     -- the DS3/E3 Current Table


     dsx3CurrentTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF Dsx3CurrentEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "The DS3/E3 current table contains various
                 statistics being collected for the current 15
                 minute interval."
          ::= { ds3 6 }

     dsx3CurrentEntry OBJECT-TYPE
          SYNTAX  Dsx3CurrentEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "An entry in the DS3/E3 Current table."
          INDEX   { dsx3CurrentIndex }
          ::= { dsx3CurrentTable 1 }

     Dsx3CurrentEntry ::=
          SEQUENCE {
              dsx3CurrentIndex           InterfaceIndex,
              dsx3CurrentPESs            PerfCurrentCount,
              dsx3CurrentPSESs           PerfCurrentCount,
              dsx3CurrentSEFSs           PerfCurrentCount,



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              dsx3CurrentUASs            PerfCurrentCount,
              dsx3CurrentLCVs            PerfCurrentCount,
              dsx3CurrentPCVs            PerfCurrentCount,
              dsx3CurrentLESs            PerfCurrentCount,
              dsx3CurrentCCVs            PerfCurrentCount,
              dsx3CurrentCESs            PerfCurrentCount,
              dsx3CurrentCSESs           PerfCurrentCount
         }

     dsx3CurrentIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The index value which uniquely identifies the
                 DS3/E3 interface to which this entry is
                 applicable.  The interface identified by a
                 particular value of this index is the same
                 interface as identified by the same value an
                 dsx3LineIndex object instance."
          ::= { dsx3CurrentEntry 1 }

     dsx3CurrentPESs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of P-bit
                 Errored Seconds."
          ::= { dsx3CurrentEntry 2 }

     dsx3CurrentPSESs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of P-bit
                 Severely Errored Seconds."
          ::= { dsx3CurrentEntry 3 }

     dsx3CurrentSEFSs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of
                 Severely Errored Framing Seconds."
          ::= { dsx3CurrentEntry 4 }



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     dsx3CurrentUASs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of
                 Unavailable Seconds."
          ::= { dsx3CurrentEntry 5 }

     dsx3CurrentLCVs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of Line
                 Coding Violations."
          ::= { dsx3CurrentEntry 6 }

     dsx3CurrentPCVs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of P-bit
                 Coding Violations."
          ::= { dsx3CurrentEntry 7 }

     dsx3CurrentLESs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of Line Errored Seconds."
          ::= { dsx3CurrentEntry 8 }

     dsx3CurrentCCVs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of C-bit Coding Violations."
          ::= { dsx3CurrentEntry 9 }

     dsx3CurrentCESs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION



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                 "The number of C-bit Errored Seconds."
          ::= { dsx3CurrentEntry 10 }

     dsx3CurrentCSESs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of C-bit Severely Errored Seconds."
          ::= { dsx3CurrentEntry 11 }

     -- the DS3/E3 Interval Table

     dsx3IntervalTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF Dsx3IntervalEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "The DS3/E3 Interval Table contains various
                 statistics collected by each DS3/E3 Interface over
                 the previous 24 hours of operation.  The past 24
                 hours are broken into 96 completed 15 minute
                 intervals.  Each row in this table represents one
                 such interval (identified by dsx3IntervalNumber)
                 and for one specific interface (identifed by
                 dsx3IntervalIndex)."

          ::= { ds3 7 }

     dsx3IntervalEntry OBJECT-TYPE
          SYNTAX  Dsx3IntervalEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "An entry in the DS3/E3 Interval table."
          INDEX   { dsx3IntervalIndex, dsx3IntervalNumber }
          ::= { dsx3IntervalTable 1 }

     Dsx3IntervalEntry ::=
          SEQUENCE {
              dsx3IntervalIndex           InterfaceIndex,
              dsx3IntervalNumber          INTEGER,
              dsx3IntervalPESs            PerfIntervalCount,
              dsx3IntervalPSESs           PerfIntervalCount,
              dsx3IntervalSEFSs           PerfIntervalCount,
              dsx3IntervalUASs            PerfIntervalCount,
              dsx3IntervalLCVs            PerfIntervalCount,
              dsx3IntervalPCVs            PerfIntervalCount,



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              dsx3IntervalLESs            PerfIntervalCount,
              dsx3IntervalCCVs            PerfIntervalCount,
              dsx3IntervalCESs            PerfIntervalCount,
              dsx3IntervalCSESs           PerfIntervalCount,
              dsx3IntervalValidData       TruthValue
          }

     dsx3IntervalIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The index value which uniquely identifies the
                 DS3/E3 interface to which this entry is
                 applicable.  The interface identified by a
                 particular value of this index is the same
                 interface as identified by the same value an
                 dsx3LineIndex object instance."
          ::= { dsx3IntervalEntry 1 }

     dsx3IntervalNumber OBJECT-TYPE
          SYNTAX  INTEGER (1..96)
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "A number between 1 and 96, where 1 is the most
                 recently completed 15 minute interval and 96 is
                 the 15 minutes interval completed 23 hours and 45
                 minutes prior to interval 1."
          ::= { dsx3IntervalEntry 2 }

     dsx3IntervalPESs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of P-bit
                 Errored Seconds."
          ::= { dsx3IntervalEntry 3 }

     dsx3IntervalPSESs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of P-bit
                 Severely Errored Seconds."
          ::= { dsx3IntervalEntry 4 }



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     dsx3IntervalSEFSs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of
                 Severely Errored Framing Seconds."
          ::= { dsx3IntervalEntry 5 }

     dsx3IntervalUASs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of
                 Unavailable Seconds.  This object may decrease if
                 the occurance of unavailable seconds occurs across
                 an inteval boundary."
          ::= { dsx3IntervalEntry 6 }

     dsx3IntervalLCVs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of Line
                 Coding Violations."
          ::= { dsx3IntervalEntry 7 }

     dsx3IntervalPCVs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of P-bit
                 Coding Violations."
          ::= { dsx3IntervalEntry 8 }

     dsx3IntervalLESs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of Line Errored  Seconds  (BPVs  or
                 illegal  zero  sequences)."
          ::= { dsx3IntervalEntry 9 }

     dsx3IntervalCCVs OBJECT-TYPE



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          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of C-bit Coding Violations."
          ::= { dsx3IntervalEntry 10 }

     dsx3IntervalCESs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of C-bit Errored Seconds."
          ::= { dsx3IntervalEntry 11 }

     dsx3IntervalCSESs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of C-bit Severely Errored Seconds."
          ::= { dsx3IntervalEntry 12 }

     dsx3IntervalValidData OBJECT-TYPE
          SYNTAX  TruthValue
          MAX-ACCESS read-only
          STATUS current
          DESCRIPTION
                 "This variable indicates if the data for this
                 interval is valid."
          ::= { dsx3IntervalEntry 13 }

     -- the DS3/E3 Total

     dsx3TotalTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF Dsx3TotalEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "The DS3/E3 Total Table contains the cumulative
                 sum of the various statistics for the 24 hour
                 period preceding the current interval."
          ::= { ds3 8 }

     dsx3TotalEntry OBJECT-TYPE
          SYNTAX  Dsx3TotalEntry
          MAX-ACCESS  not-accessible
          STATUS  current



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          DESCRIPTION
                 "An entry in the DS3/E3 Total table."
         INDEX   { dsx3TotalIndex }
          ::= { dsx3TotalTable 1 }

     Dsx3TotalEntry ::=
          SEQUENCE {
              dsx3TotalIndex      InterfaceIndex,
              dsx3TotalPESs       PerfTotalCount,
              dsx3TotalPSESs      PerfTotalCount,
              dsx3TotalSEFSs      PerfTotalCount,
              dsx3TotalUASs       PerfTotalCount,
              dsx3TotalLCVs       PerfTotalCount,
              dsx3TotalPCVs       PerfTotalCount,
              dsx3TotalLESs       PerfTotalCount,
              dsx3TotalCCVs       PerfTotalCount,
              dsx3TotalCESs       PerfTotalCount,
              dsx3TotalCSESs      PerfTotalCount
          }

     dsx3TotalIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The index value which uniquely identifies the
                 DS3/E3 interface to which this entry is
                 applicable.  The interface identified by a
                 particular value of this index is the same
                 interface as identified by the same value an
                 dsx3LineIndex object instance."
          ::= { dsx3TotalEntry 1 }

     dsx3TotalPESs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of P-bit
                 Errored Seconds, encountered by a DS3 interface in
                 the previous 24 hour interval. Invalid 15 minute
                 intervals count as 0."
          ::= { dsx3TotalEntry 2 }

     dsx3TotalPSESs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current



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          DESCRIPTION
                 "The counter associated with the number of P-bit
                 Severely Errored Seconds, encountered by a DS3
                 interface in the previous 24 hour interval.
                 Invalid 15 minute intervals count as 0."
          ::= { dsx3TotalEntry 3 }

     dsx3TotalSEFSs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of
                 Severely Errored Framing Seconds, encountered by a
                 DS3/E3 interface in the previous 24 hour interval.
                 Invalid 15 minute intervals count as 0."
          ::= { dsx3TotalEntry 4 }

     dsx3TotalUASs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of
                 Unavailable Seconds, encountered by a DS3
                 interface in the previous 24 hour interval.

                 Invalid 15 minute intervals count as 0."
          ::= { dsx3TotalEntry 5 }

     dsx3TotalLCVs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of Line
                 Coding Violations encountered by a DS3/E3
                 interface in the previous 24 hour interval.
                 Invalid 15 minute intervals count as 0."
          ::= { dsx3TotalEntry 6 }

     dsx3TotalPCVs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of P-bit
                 Coding Violations, encountered by a DS3 interface



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                 in the previous 24 hour interval. Invalid 15
                 minute intervals count as 0."
          ::= { dsx3TotalEntry 7 }

     dsx3TotalLESs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of Line Errored  Seconds  (BPVs  or
                 illegal  zero  sequences) encountered by a DS3/E3
                 interface in the previous 24 hour interval.
                 Invalid 15 minute intervals count as 0."
          ::= { dsx3TotalEntry 8 }

     dsx3TotalCCVs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of C-bit Coding Violations encountered
                 by a DS3 interface in the previous 24 hour
                 interval. Invalid 15 minute intervals count as 0."
          ::= { dsx3TotalEntry 9 }

     dsx3TotalCESs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of C-bit Errored Seconds encountered
                 by a DS3 interface in the previous 24 hour
                 interval. Invalid 15 minute intervals count as 0."
          ::= { dsx3TotalEntry 10 }

     dsx3TotalCSESs OBJECT-TYPE
          SYNTAX  PerfTotalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of C-bit Severely Errored Seconds
                 encountered by a DS3 interface in the previous 24
                 hour interval. Invalid 15 minute intervals count
                 as 0."
          ::= { dsx3TotalEntry 11 }


     -- The DS3 Far End Group



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     -- The DS3 Far End Group consists of four tables :
     --   DS3 Far End Configuration
     --   DS3 Far End Current
     --   DS3 Far End Interval
     --   DS3 Far End Total


     -- The DS3 Far End Configuration Table

     dsx3FarEndConfigTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF Dsx3FarEndConfigEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "The DS3 Far End Configuration Table contains
                 configuration information reported in the C-bits
                 from the remote end."
          ::= { ds3 9 }

     dsx3FarEndConfigEntry OBJECT-TYPE
          SYNTAX  Dsx3FarEndConfigEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "An entry in the DS3 Far End Configuration table."
         INDEX   { dsx3FarEndLineIndex }
          ::= { dsx3FarEndConfigTable 1 }

     Dsx3FarEndConfigEntry ::=
          SEQUENCE {
              dsx3FarEndLineIndex          InterfaceIndex,
             dsx3FarEndEquipCode           DisplayString,
             dsx3FarEndLocationIDCode      DisplayString,
             dsx3FarEndFrameIDCode         DisplayString,
             dsx3FarEndUnitCode            DisplayString,
             dsx3FarEndFacilityIDCode      DisplayString
          }

     dsx3FarEndLineIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The index value which uniquely identifies the DS3
                 interface to which this entry is applicable.  The
                 interface identified by a particular value of this
                 index is the same interface as identified by the
                 same value an dsx3LineIndex object instance."



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         ::= { dsx3FarEndConfigEntry 1 }

     dsx3FarEndEquipCode OBJECT-TYPE
          SYNTAX  DisplayString (SIZE (0..10))
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
                 "This is the Far End Equipment Identification code
                 that describes the specific piece of equipment.
                 It is sent within the Path Identification
                 Message."
          ::= { dsx3FarEndConfigEntry 2 }

     dsx3FarEndLocationIDCode OBJECT-TYPE
          SYNTAX  DisplayString (SIZE (0..11))
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
                 "This is the Far End Location Identification code
                 that describes the specific location of the
                 equipment.  It is sent within the Path
                 Identification Message."
          ::= { dsx3FarEndConfigEntry 3 }

     dsx3FarEndFrameIDCode OBJECT-TYPE
          SYNTAX  DisplayString (SIZE (0..10))
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
                 "This is the Far End Frame Identification code
                 that identifies where the equipment is located
                 within a building at a given location.  It is sent
                 within the Path Identification Message."
          ::= { dsx3FarEndConfigEntry 4 }

     dsx3FarEndUnitCode OBJECT-TYPE
          SYNTAX  DisplayString (SIZE (0..6))
          MAX-ACCESS  read-write
          STATUS  current
          DESCRIPTION
                 "This is the Far End code that identifies the
                 equipment location within a bay.  It is sent
                 within the Path Identification Message."
          ::= { dsx3FarEndConfigEntry 5 }

     dsx3FarEndFacilityIDCode OBJECT-TYPE
          SYNTAX  DisplayString (SIZE (0..38))
          MAX-ACCESS  read-write



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          STATUS  current
          DESCRIPTION
                 "This code identifies a specific Far End DS3 path.
                 It is sent within the Path Identification
                 Message."
          ::= { dsx3FarEndConfigEntry 6 }

     -- The DS3 Far End Current

     dsx3FarEndCurrentTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF Dsx3FarEndCurrentEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "The DS3 Far End Current table contains various
                 statistics being collected for the current 15
                 minute interval.  The statistics are collected
                 from the far end block error code within the C-
                 bits."
          ::= { ds3 10 }

     dsx3FarEndCurrentEntry OBJECT-TYPE
          SYNTAX  Dsx3FarEndCurrentEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "An entry in the DS3 Far End Current table."
          INDEX   { dsx3FarEndCurrentIndex }
          ::= { dsx3FarEndCurrentTable 1 }

     Dsx3FarEndCurrentEntry ::=
          SEQUENCE {
              dsx3FarEndCurrentIndex        InterfaceIndex,
              dsx3FarEndTimeElapsed         INTEGER,
              dsx3FarEndValidIntervals      INTEGER,
              dsx3FarEndCurrentCESs         PerfCurrentCount,
              dsx3FarEndCurrentCSESs        PerfCurrentCount,
              dsx3FarEndCurrentCCVs         PerfCurrentCount,
              dsx3FarEndCurrentUASs         PerfCurrentCount,
              dsx3FarEndInvalidIntervals    INTEGER
         }

      dsx3FarEndCurrentIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The index value which uniquely identifies the DS3



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                 interface to which this entry is applicable.  The
                 interface identified by a particular value of this
                 index is identical to the interface identified by
                 the same value of dsx3LineIndex."
          ::= { dsx3FarEndCurrentEntry 1 }

     dsx3FarEndTimeElapsed OBJECT-TYPE
          SYNTAX  INTEGER (0..899)
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of seconds that have elapsed since the
                 beginning of the far end current error-measurement
                 period.  If, for some reason, such as an
                 adjustment in the system's time-of-day clock, the
                 current interval exceeds the maximum value, the
                 agent will return the maximum value."
          ::= { dsx3FarEndCurrentEntry 2 }

     dsx3FarEndValidIntervals OBJECT-TYPE
          SYNTAX  INTEGER (0..96)
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of previous far end intervals for
                 which data was collected.  The value will be
                 96 unless the interface was brought online within
                 the last 24 hours, in which case the value will be
                 the number of complete 15 minute far end intervals
                 since the interface has been online."
          ::= { dsx3FarEndCurrentEntry 3 }

     dsx3FarEndCurrentCESs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of Far Far
                 End C-bit Errored Seconds."
          ::= { dsx3FarEndCurrentEntry 4 }

     dsx3FarEndCurrentCSESs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of Far End
                 C-bit Severely Errored Seconds."



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          ::= { dsx3FarEndCurrentEntry 5 }

     dsx3FarEndCurrentCCVs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of Far End
                 C-bit Coding Violations reported via the far end
                 block error count."
          ::= { dsx3FarEndCurrentEntry 6 }

     dsx3FarEndCurrentUASs OBJECT-TYPE
          SYNTAX  PerfCurrentCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of Far End
                 unavailable seconds."
          ::= { dsx3FarEndCurrentEntry 7 }

     dsx3FarEndInvalidIntervals OBJECT-TYPE
          SYNTAX  INTEGER (0..96)
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The number of intervals in the range from 0 to
                 dsx3FarEndValidIntervals for which no data is
                 available.  This object will typically be zero
                 except in cases where the data for some intervals
                 are not available (e.g., in proxy situations)."
          ::= { dsx3FarEndCurrentEntry 8 }

     -- The DS3 Far End Interval Table

     dsx3FarEndIntervalTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF Dsx3FarEndIntervalEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "The DS3 Far End Interval Table contains various
                 statistics collected by each DS3 interface over
                 the previous 24 hours of operation.  The past 24
                 hours are broken into 96 completed 15 minute
                 intervals."
          ::= { ds3 11 }

     dsx3FarEndIntervalEntry OBJECT-TYPE



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          SYNTAX  Dsx3FarEndIntervalEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "An entry in the DS3 Far End Interval table."
          INDEX   { dsx3FarEndIntervalIndex,
                    dsx3FarEndIntervalNumber }
          ::= { dsx3FarEndIntervalTable 1 }

     Dsx3FarEndIntervalEntry ::=
          SEQUENCE {
               dsx3FarEndIntervalIndex      InterfaceIndex,
               dsx3FarEndIntervalNumber     INTEGER,
               dsx3FarEndIntervalCESs       PerfIntervalCount,
               dsx3FarEndIntervalCSESs      PerfIntervalCount,
               dsx3FarEndIntervalCCVs       PerfIntervalCount,
               dsx3FarEndIntervalUASs       PerfIntervalCount,
               dsx3FarEndIntervalValidData  TruthValue
         }

     dsx3FarEndIntervalIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The index value which uniquely identifies the DS3
                 interface to which this entry is applicable.  The
                 interface identified by a particular value of this
                 index is identical to the interface identified by
                 the same value of dsx3LineIndex."
          ::= { dsx3FarEndIntervalEntry 1 }

     dsx3FarEndIntervalNumber OBJECT-TYPE
         SYNTAX  INTEGER (1..96)
         MAX-ACCESS  read-only
         STATUS  current
         DESCRIPTION
                 "A number between 1 and 96, where 1 is the most
                 recently completed 15 minute interval and 96 is
                 the 15 minutes interval completed 23 hours and 45
                 minutes prior to interval 1."
         ::= { dsx3FarEndIntervalEntry 2 }

     dsx3FarEndIntervalCESs OBJECT-TYPE
         SYNTAX  PerfIntervalCount
         MAX-ACCESS  read-only
         STATUS  current
         DESCRIPTION



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                 "The counter associated with the number of Far End
                 C-bit Errored Seconds encountered by a DS3
                 interface in one of the previous 96, individual 15
                 minute, intervals. In the case where the agent is
                 a proxy and data is not available, return
                 noSuchInstance."
        ::= { dsx3FarEndIntervalEntry 3 }

     dsx3FarEndIntervalCSESs OBJECT-TYPE
         SYNTAX  PerfIntervalCount
         MAX-ACCESS  read-only
         STATUS  current
         DESCRIPTION
                 "The counter associated with the number of Far End
                 C-bit Severely Errored Seconds."
        ::= { dsx3FarEndIntervalEntry 4 }

     dsx3FarEndIntervalCCVs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of Far End
                 C-bit Coding Violations reported via the far end
                 block error count."
          ::= { dsx3FarEndIntervalEntry 5 }

     dsx3FarEndIntervalUASs OBJECT-TYPE
          SYNTAX  PerfIntervalCount
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The counter associated with the number of Far End
                 unavailable seconds."
          ::= { dsx3FarEndIntervalEntry 6 }

     dsx3FarEndIntervalValidData OBJECT-TYPE
          SYNTAX  TruthValue
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "This variable indicates if the data for this
                 interval is valid."
          ::= { dsx3FarEndIntervalEntry 7 }


     -- The DS3 Far End Total




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     dsx3FarEndTotalTable OBJECT-TYPE
          SYNTAX  SEQUENCE OF Dsx3FarEndTotalEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "The DS3 Far End Total Table contains the
                 cumulative sum of the various statistics for the
                 24 hour period preceding the current interval."
          ::= { ds3 12 }

     dsx3FarEndTotalEntry OBJECT-TYPE
          SYNTAX  Dsx3FarEndTotalEntry
          MAX-ACCESS  not-accessible
          STATUS  current
          DESCRIPTION
                 "An entry in the DS3 Far End Total table."
          INDEX   { dsx3FarEndTotalIndex }
          ::= { dsx3FarEndTotalTable 1 }

     Dsx3FarEndTotalEntry ::=
          SEQUENCE {
              dsx3FarEndTotalIndex       InterfaceIndex,
              dsx3FarEndTotalCESs        PerfTotalCount,
              dsx3FarEndTotalCSESs       PerfTotalCount,
              dsx3FarEndTotalCCVs        PerfTotalCount,
              dsx3FarEndTotalUASs        PerfTotalCount
          }

     dsx3FarEndTotalIndex OBJECT-TYPE
          SYNTAX  InterfaceIndex
          MAX-ACCESS  read-only
          STATUS  current
          DESCRIPTION
                 "The index value which uniquely identifies the DS3
                 interface to which this entry is applicable.  The
                 interface identified by a particular value of this
                 index is identical to the interface identified by
                 the same value of dsx3LineIndex."
          ::= { dsx3FarEndTotalEntry 1 }

     dsx3FarEndTotalCESs OBJECT-TYPE
         SYNTAX  PerfTotalCount
         MAX-ACCESS  read-only
         STATUS  current
         DESCRIPTION
                 "The counter associated with the number of Far End
                 C-bit Errored Seconds encountered by a DS3
                 interface in the previous 24 hour interval.



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                 Invalid 15 minute intervals count as 0."
         ::= { dsx3FarEndTotalEntry 2 }

     dsx3FarEndTotalCSESs OBJECT-TYPE
         SYNTAX  PerfTotalCount
         MAX-ACCESS  read-only
         STATUS  current
         DESCRIPTION
                 "The counter associated with the number of Far End
                 C-bit Severely Errored Seconds encountered by a
                 DS3 interface in the previous 24 hour interval.
                 Invalid 15 minute intervals count as 0."
         ::= { dsx3FarEndTotalEntry 3 }

     dsx3FarEndTotalCCVs OBJECT-TYPE
         SYNTAX  PerfTotalCount
         MAX-ACCESS  read-only
         STATUS  current
         DESCRIPTION
                 "The counter associated with the number of Far End
                 C-bit Coding Violations reported via the far end
                 block error count encountered by a DS3 interface
                 in the previous 24 hour interval. Invalid 15
                 minute intervals count as 0."
         ::= { dsx3FarEndTotalEntry 4 }

     dsx3FarEndTotalUASs OBJECT-TYPE
         SYNTAX  PerfTotalCount
         MAX-ACCESS  read-only
         STATUS  current
         DESCRIPTION
                 "The counter associated with the number of Far End
                 unavailable seconds encountered by a DS3 interface
                 in the previous 24 hour interval.  Invalid 15
                 minute intervals count as 0."
         ::= { dsx3FarEndTotalEntry 5 }


     -- the DS3/E3 Fractional Table

     -- This table is deprecated.

     dsx3FracTable OBJECT-TYPE
         SYNTAX  SEQUENCE OF Dsx3FracEntry
         MAX-ACCESS  not-accessible
         STATUS  deprecated
         DESCRIPTION
                 "This table is deprecated in favour of using



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                 ifStackTable.

                 Implementation of this table was optional.  It was
                 designed for those systems dividing a DS3/E3 into
                 channels containing different data streams that
                 are of local interest.

                 The DS3/E3 fractional table identifies which
                 DS3/E3 channels associated with a CSU are being
                 used to support a logical interface, i.e., an
                 entry in the interfaces table from the Internet-
                 standard MIB.

                 For example, consider a DS3 device with 4 high
                 speed links carrying router traffic, a feed for
                 voice, a feed for video, and a synchronous channel
                 for a non-routed protocol.  We might describe the
                 allocation of channels, in the dsx3FracTable, as
                 follows:
                 dsx3FracIfIndex.2. 1 = 3  dsx3FracIfIndex.2.15 = 4
                 dsx3FracIfIndex.2. 2 = 3  dsx3FracIfIndex.2.16 = 6
                 dsx3FracIfIndex.2. 3 = 3  dsx3FracIfIndex.2.17 = 6
                 dsx3FracIfIndex.2. 4 = 3  dsx3FracIfIndex.2.18 = 6
                 dsx3FracIfIndex.2. 5 = 3  dsx3FracIfIndex.2.19 = 6
                 dsx3FracIfIndex.2. 6 = 3  dsx3FracIfIndex.2.20 = 6
                 dsx3FracIfIndex.2. 7 = 4  dsx3FracIfIndex.2.21 = 6
                 dsx3FracIfIndex.2. 8 = 4  dsx3FracIfIndex.2.22 = 6
                 dsx3FracIfIndex.2. 9 = 4  dsx3FracIfIndex.2.23 = 6
                 dsx3FracIfIndex.2.10 = 4  dsx3FracIfIndex.2.24 = 6
                 dsx3FracIfIndex.2.11 = 4  dsx3FracIfIndex.2.25 = 6
                 dsx3FracIfIndex.2.12 = 5  dsx3FracIfIndex.2.26 = 6
                 dsx3FracIfIndex.2.13 = 5  dsx3FracIfIndex.2.27 = 6
                 dsx3FracIfIndex.2.14 = 5  dsx3FracIfIndex.2.28 = 6
                 For dsx3M23, dsx3 SYNTRAN, dsx3CbitParity, and
                 dsx3ClearChannel  there are 28 legal channels,
                 numbered 1 throug h 28.

                 For e3Framed there are 16 legal channels, numbered
                 1 through 16.  The channels (1..16) correspond
                 directly to the equivalently numbered time-slots."
          ::= { ds3 13 }

     dsx3FracEntry OBJECT-TYPE
          SYNTAX  Dsx3FracEntry
          MAX-ACCESS  not-accessible
          STATUS  deprecated
          DESCRIPTION
                         "An entry in the DS3 Fractional table."



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         INDEX   { dsx3FracIndex, dsx3FracNumber }
         ::= { dsx3FracTable 1 }

     Dsx3FracEntry ::=
          SEQUENCE {
              dsx3FracIndex     INTEGER,
              dsx3FracNumber    INTEGER,
              dsx3FracIfIndex   INTEGER
         }


     dsx3FracIndex OBJECT-TYPE
         SYNTAX  INTEGER (1..'7fffffff'h)
         MAX-ACCESS  read-only
         STATUS  deprecated
         DESCRIPTION
                 "The index value which uniquely identifies  the
                 DS3  interface  to which this entry is applicable
                 The interface identified by a  particular value
                 of  this  index is the same interface as
                 identified by the same value  an  dsx3LineIndex
                 object instance."
        ::= { dsx3FracEntry 1 }

     dsx3FracNumber OBJECT-TYPE
         SYNTAX  INTEGER (1..31)
         MAX-ACCESS  read-only
         STATUS  deprecated
         DESCRIPTION
                 "The channel number for this entry."
        ::= { dsx3FracEntry 2 }

     dsx3FracIfIndex OBJECT-TYPE
         SYNTAX  INTEGER (1..'7fffffff'h)
         MAX-ACCESS  read-write
         STATUS  deprecated
         DESCRIPTION
                 "An index value that uniquely identifies an
                 interface.  The interface identified by a
                 particular value of this index is the same
                 interface as  identified by the same value an
                 ifIndex object instance. If no interface is
                 currently using a channel, the value should be
                 zero.  If a single interface occupies more  than
                 one  time slot,  that ifIndex value will be found
                 in multiple time slots."
        ::= { dsx3FracEntry 3 }




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      -- Ds3 TRAPS

     ds3Traps OBJECT IDENTIFIER ::= { ds3 15 }



     dsx3LineStatusChange NOTIFICATION-TYPE
         OBJECTS { dsx3LineStatus,
                   dsx3LineStatusLastChange }
         STATUS  current
         DESCRIPTION
                 "A dsx3LineStatusChange trap is sent when the
                 value of an instance of dsx3LineStatus changes. It
                 can be utilized by an NMS to trigger polls.  When
                 the line status change results in a lower level
                 line status change (i.e. ds1), then no traps for
                 the lower level are sent."
                    ::= { ds3Traps 0 1 }


                 -- conformance information

                 ds3Conformance OBJECT IDENTIFIER ::= { ds3 14 }

                 ds3Groups      OBJECT IDENTIFIER ::= {
                 ds3Conformance 1 } ds3Compliances OBJECT
                 IDENTIFIER ::= { ds3Conformance 2 }



                 -- compliance statements

                 ds3Compliance MODULE-COMPLIANCE
                     STATUS  current
                     DESCRIPTION
                             "The compliance statement for DS3/E3
                             interfaces."
         MODULE  -- this module
             MANDATORY-GROUPS { ds3NearEndConfigGroup,
                                ds3NearEndStatisticsGroup }

             GROUP       ds3FarEndGroup
             DESCRIPTION
                 "Implementation of this group is optional for all
                 systems that attach to a DS3 Interface.  However,
                 only C-bit Parity and SYNTRAN DS3 applications
                 have the capability (option) of providing this
                 information."



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             GROUP       ds3NearEndOptionalConfigGroup
             DESCRIPTION
                 "Implementation of this group is optional for all
                 systems that attach to a DS3 interface."

             OBJECT      dsx3LineType
             MIN-ACCESS  read-only
             DESCRIPTION
                 "Write access for the line type is not required."

             OBJECT      dsx3LineCoding
             MIN-ACCESS  read-only
             DESCRIPTION
                 "Write access for the line coding is not
                 required."

             OBJECT      dsx3SendCode
             MIN-ACCESS  read-only
             DESCRIPTION
                 "Write access for the send code is not required."

             OBJECT      dsx3LoopbackConfig
             MIN-ACCESS  read-only
             DESCRIPTION
                 "Write access for loopbacks is not required."

             OBJECT      dsx3TransmitClockSource
             MIN-ACCESS  read-only
             DESCRIPTION
                 "Write access for the transmit clock source is not
                 required."

             OBJECT      dsx3LineLength
             MIN-ACCESS  read-only
             DESCRIPTION
                 "Write access for the line length is not
                 required."

             OBJECT      dsx3Channelization
             MIN-ACCESS  read-only
             DESCRIPTION
                 "Write access for the channelization is not
                 required."

         ::= { ds3Compliances 1 }

     -- units of conformance




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     ds3NearEndConfigGroup  OBJECT-GROUP
         OBJECTS { dsx3LineIndex,
                   dsx3TimeElapsed,
                   dsx3ValidIntervals,
                   dsx3LineType,
                   dsx3LineCoding,
                   dsx3SendCode,
                   dsx3CircuitIdentifier,
                   dsx3LoopbackConfig,
                   dsx3LineStatus,
                   dsx3TransmitClockSource,
                   dsx3InvalidIntervals,
                   dsx3LineLength,
                   dsx3LoopbackStatus,
                   dsx3Channelization,
                   dsx3Ds1ForRemoteLoop }
         STATUS  current
         DESCRIPTION
                 "A collection of objects providing configuration
                 information applicable to all DS3/E3 interfaces."
         ::= { ds3Groups 1 }

     ds3NearEndStatisticsGroup OBJECT-GROUP
         OBJECTS { dsx3CurrentIndex,
                   dsx3CurrentPESs,
                   dsx3CurrentPSESs,
                   dsx3CurrentSEFSs,
                   dsx3CurrentUASs,
                   dsx3CurrentLCVs,
                   dsx3CurrentPCVs,
                   dsx3CurrentLESs,
                   dsx3CurrentCCVs,
                   dsx3CurrentCESs,
                   dsx3CurrentCSESs,
                   dsx3IntervalIndex,
                   dsx3IntervalNumber,
                   dsx3IntervalPESs,
                   dsx3IntervalPSESs,
                   dsx3IntervalSEFSs,
                   dsx3IntervalUASs,
                   dsx3IntervalLCVs,
                   dsx3IntervalPCVs,
                   dsx3IntervalLESs,
                   dsx3IntervalCCVs,
                   dsx3IntervalCESs,
                   dsx3IntervalCSESs,
                   dsx3IntervalValidData,
                   dsx3TotalIndex,



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                   dsx3TotalPESs,
                   dsx3TotalPSESs,
                   dsx3TotalSEFSs,
                   dsx3TotalUASs,
                   dsx3TotalLCVs,
                   dsx3TotalPCVs,
                   dsx3TotalLESs,
                   dsx3TotalCCVs,
                   dsx3TotalCESs,
                   dsx3TotalCSESs }
         STATUS  current
         DESCRIPTION
                 "A collection of objects providing statistics
                 information applicable to all DS3/E3 interfaces."
         ::= { ds3Groups 2 }

     ds3FarEndGroup  OBJECT-GROUP
         OBJECTS { dsx3FarEndLineIndex,
                   dsx3FarEndEquipCode,
                   dsx3FarEndLocationIDCode,
                   dsx3FarEndFrameIDCode,
                   dsx3FarEndUnitCode,
                   dsx3FarEndFacilityIDCode,
                   dsx3FarEndCurrentIndex,
                   dsx3FarEndTimeElapsed,
                   dsx3FarEndValidIntervals,
                   dsx3FarEndCurrentCESs,
                   dsx3FarEndCurrentCSESs,
                   dsx3FarEndCurrentCCVs,
                   dsx3FarEndCurrentUASs,
                   dsx3FarEndInvalidIntervals,
                   dsx3FarEndIntervalIndex,
                   dsx3FarEndIntervalNumber,
                   dsx3FarEndIntervalCESs,
                   dsx3FarEndIntervalCSESs,
                   dsx3FarEndIntervalCCVs,
                   dsx3FarEndIntervalUASs,
                   dsx3FarEndIntervalValidData,
                   dsx3FarEndTotalIndex,
                   dsx3FarEndTotalCESs,
                   dsx3FarEndTotalCSESs,
                   dsx3FarEndTotalCCVs,
                   dsx3FarEndTotalUASs }
         STATUS  current
         DESCRIPTION
                 "A collection of objects providing remote
                 configuration and statistics information
                 applicable to C-bit Parity and SYNTRAN DS3



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                 interfaces."
         ::= { ds3Groups 3 }

     ds3DeprecatedGroup OBJECT-GROUP
         OBJECTS { dsx3IfIndex,
                   dsx3FracIndex,
                   dsx3FracNumber,
                   dsx3FracIfIndex }
         STATUS  deprecated
         DESCRIPTION
                 "A collection of obsolete objects that may be
                 implemented for backwards compatibility."
         ::= { ds3Groups 4 }

     ds3NearEndOptionalConfigGroup OBJECT-GROUP
         OBJECTS { dsx3LineStatusLastChange,
                   dsx3LineStatusChangeTrapEnable }

         STATUS    current
         DESCRIPTION
                 "A collection of objects that may be implemented
                 on DS3/E3 interfaces."
         ::= { ds3Groups 5 }

     ds3NearEndOptionalTrapGroup NOTIFICATION-GROUP
         NOTIFICATIONS { dsx3LineStatusChange }
         STATUS    current
         DESCRIPTION
                 "A collection of notifications that may be
                 implemented on DS3/E3 interfaces."
         ::= { ds3Groups 6 }

     END


















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4.  Appendix A - Use of dsx3IfIndex and dsx3LineIndex

   This Appendix exists to document the previous use if dsx3IfIndex and
   dsx3LineIndex and to clarify the relationship of dsx3LineIndex as
   defined in rfc1407 with the dsx3LineIndex as defined in this
   document.

   The following shows the old and new definitions and the relationship:

   [New Definition]: "This object should be made equal to ifIndex.  The
   next paragraph describes its previous usage.  Making the object equal
   to ifIndex allows proper use of ifStackTable.

   [Old Definition]: "this object is the identifier of a DS3/E3
   Interface on a managed device.  If there is an ifEntry that is
   directly associated with this and only this DS3/E3 interface, it
   should have the same value as ifIndex.  Otherwise, number the
   dsx3LineIndices with an unique identifier following the rules of
   choosing a number that is greater than ifNumber and numbering the
   inside interfaces (e.g., equipment side) with even numbers and
   outside interfaces (e.g, network side) with odd numbers."

   When the "Old Definition" was created, my understanding was that it
   was described this way to allow a manager to treat the value _as if_
   it were and ifIndex, i.e. the value would either be:  1) an ifIndex
   value or 2) a value that was guaranteed to be different from all
   valid ifIndex values.

   The new definition is a subset of that definition, i.e. the value is
   always an ifIndex value.

   The following is Section 3.1 from rfc1407:

   Different physical configurations for the support of SNMP with DS3/E3
   equipment exist. To accommodate these scenarios, two different
   indices for DS3/E3 interfaces are introduced in this MIB.  These
   indices are dsx3IfIndex and dsx3LineIndex.

   External interface scenario: the SNMP Agent represents all managed
   DS3/E3 lines as external interfaces (for example, an Agent residing
   on the device supporting DS3/E3 interfaces directly):

   For this scenario, all interfaces are assigned an integer value equal
   to ifIndex, and the following applies:

      ifIndex=dsx3IfIndex=dsx3LineIndex for all interfaces.





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   The dsx3IfIndex column of the DS3/E3 Configuration table relates each
   DS3/E3 interface to its corresponding interface (ifIndex) in the
   Internet-standard MIB (MIB-II STD 17, RFC1213).

   External&Internal interface scenario: the SNMP Agents resides on an
   host external from the device supporting DS3/E3 interfaces (e.g., a
   router). The Agent represents both the host and the DS3/E3 device.
   The index dsx3LineIndex is used to not only represent the DS3/E3
   interfaces external from the host/DS3/E3-device combination, but also
   the DS3/E3 interfaces connecting the host and the DS3/E3 device.  The
   index dsx3IfIndex is always equal to ifIndex.

   Example:

   A shelf full of CSUs connected to a Router. An SNMP Agent residing on
   the router proxies for itself and the CSU. The router has also an
   Ethernet interface:

         +-----+
   |     |     |
   |     |     |               +---------------------+
   |E    |     |  44.736 MBPS  |   ds3 M13    Line#A | ds3 C-bit Parity
   |t    |  R  |---------------+ - - - - -  - - -  - +------>
   |h    |     |               |                     |
   |e    |  O  |  44.736 MBPS  |   ds3 M13    Line#B | ds3 C-bit Parity
   |r    |     |---------------+ - - - - - - - - - - +------>
   |n    |  U  |               |                     |
   |e    |     |  44.736 MBPS  |   ds3 M13    Line#C | ds3 C-bit Parity
   |t    |  T  |---------------+ - - - -- -- - - - - +------>
   |     |     |               |                     |
   |-----|  E  |  44.736 MBPS  |   ds3 M13    Line#D | ds3 C-bit Parity
   |     |     |---------------+ -  - - - -- - - - - +------>
   |     |  R  |               |_____________________|
   |     |     |
   |     +-----+
















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   The assignment of the index values could for example be:

           ifIndex (= dsx3IfIndex)                     dsx3LineIndex

                   1                   NA                  NA (Ethernet)
                   2      Line#A   Router Side             6
                   2      Line#A   Network Side            7
                   3      Line#B   Router Side             8
                   3      Line#B   Network Side            9
                   4      Line#C   Router Side            10
                   4      Line#C   Network Side           11
                   5      Line#D   Router Side            12
                   5      Line#D   Network Side           13

   For this example, ifNumber is equal to 5.  Note the following
   description of dsx3LineIndex:  the dsx3LineIndex identifies a DS3/E3
   Interface on a managed device.  If there is an ifEntry that is
   directly associated with this and only this DS3/E3 interface, it
   should have the same value as ifIndex.  Otherwise, number the
   dsx3LineIndices with an unique identifier following the rules of
   choosing a number greater than ifNumber and numbering inside
   interfaces (e.g., equipment side) with even numbers and outside
   interfaces (e.g, network side) with odd numbers.

   If the CSU shelf is managed by itself by a local SNMP Agent, the
   situation would be:

           ifIndex (= dsx3IfIndex)                      dsx3LineIndex

                   1      Line#A     Network Side            1
                   2      Line#A     RouterSide              2
                   3      Line#B     Network Side            3
                   4      Line#B     RouterSide              4
                   5      Line#C     Network Side            5
                   6      Line#C     Router Side             6
                   7      Line#D     Network Side            7
                   8      Line#D     Router Side             8














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5.  Appendix B - The delay approach to Unavialable Seconds.

   This procedure is illustrated below for a DS3 C-Bit parity
   application.  Similar rules would apply for other interfaces covered
   by this MIB.  The procedure guarantees that the statistical counters
   are correctly updated at all times, although they lag real time by 10
   seconds.  At the end of each 15 minutes interval the current interval
   counts are transferred to the  most recent interval entry and each
   interval is shifted up by one position, with the oldest being
   discarded if necessary in order to make room.  The current interval
   counts then start over from zero.  Note, however, that the signal
   state calculation does not start afresh at each interval boundary;
   rather, signal state information is retained across interval
   boundaries.

   +----------------------------------------------------------------+
   |           READ COUNTERS & STATUS INFO FROM HARDWARE            |
   |                                                                |
   |BPV EXZ LOS     PCV CCV AIS SEF OOF LOF         FEBE  RAI       |
   +----------------------------------------------------------------+
     |   |   |       |   |   |   |   |   |            |    |
     |   |   |       |   |   |   |   |   |            |    |
     V   V   V       V   V   V   V   V   V            V    V
   +----------------------------------------------------------------+
   | ACCUM ONE-SEC STATS, CHK ERR THRESHOLDS, & UPDT SIGNAL STATE   |
   |                                                                |
   |<------------- NEAR END ---------------->| |<---- FAR END ----->|
   |                                                                |
   |LCV LES PCV CCV PES CES PSES CSES SEFS A/U CCV CES CSES SEFS A/U|
   +----------------------------------------------------------------+
     |   |   |   |   |   |    |    |    |   |   |   |    |    |   |
     |   |   |   |   |   |    |    |    |   |   |   |    |    |   |
     V   V   V   V   V   V    V    V    V   |   V   V    V    V   |
   +--------------------------------------+ | +-----------------+ |
   |            ONE-SEC DELAY             | | | ONE-SEC DELAY   | |
   |              (1 OF 10)               | | |   (1 OF 10)     | |
   +--------------------------------------+ | +-----------------+ |
     |   |   |   |   |   |    |    |    |   |   |   |    |    |   |
     /   /   /   /   /   /    /    /    /   /   /   /    /    /   /
     |   |   |   |   |   |    |    |    |   |   |   |    |    |   |
     V   V   V   V   V   V    V    V    V   |   V   V    V    V   |
   +--------------------------------------+ | +-----------------+ |
   |            ONE-SEC DELAY             | | | ONE-SEC DELAY   | |
   |             (10 OF 10)               | | |  (10 OF 10)     | |
   +--------------------------------------+ | +-----------------+ |
     |   |   |   |   |   |    |    |    |   |   |   |    |    |   |
     |   |   |   |   |   |    |    |    |   |   |   |    |    |   |
     V   V   V   V   V   V    V    V    V   V   V   V    V    V   V



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   +----------------------------------------------------------------+
   |               UPDATE STATISTICS COUNTERS                       |
   |                                                                |
   |<------------- NEAR END ---------------->| |<---- FAR END ----->|
   |                                                                |
   |LCV LES PCV CCV PES CES PSES CSES SEFS UAS CCV CES CSES SEFS UAS|
   +----------------------------------------------------------------+

   Note that if such a procedure is adopted there is no current interval
   data for the first ten seconds after a system comes up.
   noSuchInstance must be returned if a management station attempts to
   access the current interval counters during this time.

   It is an implementation-specific matter whether an agent assumes that
   the initial state of the interface is available or unavailable.




































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6.  Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights.  Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in BCP-11.  Copies of
   claims of rights made available for publication and any assurances of
   licenses to be made available, or the result of an attempt made to
   obtain a general license or permission for the use of such
   proprietary rights by implementors or users of this specification can
   be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard.  Please address the information to the IETF Executive
   Director.

7.  Acknowledgments

   This document was produced by the Trunk MIB Working Group

8.  References

   [1]  Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for
        Describing SNMP Management Frameworks", RFC 2271, January 1998.

   [2]  Rose, M. and K. McCloghrie, "Structure and Identification of
        Management Information for TCP/IP-based Internets", STD 16, RFC
        1155, May 1990.

   [3]  Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16,
        RFC 1212, March 1991.

   [4]  Rose, M., "A Convention for Defining Traps for use with the
        SNMP", RFC 1215, March 1991.

   [5]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Structure
        of Management Information for Version 2 of the Simple Network
        Management Protocol (SNMPv2)", RFC 1902, January 1996.

   [6]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Textual
        Conventions for Version 2 of the Simple Network Management
        Protocol (SNMPv2)", RFC 1903, January 1996.



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   [7]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
        "Conformance Statements for Version 2 of the Simple Network
        Management Protocol (SNMPv2)", RFC 1904, January 1996.

   [8]  Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple
        Network Management Protocol", STD 15, RFC 1157, May 1990.

   [9]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
        "Introduction to Community-based SNMPv2", RFC 1901, January
        1996.

   [10] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Transport
        Mappings for Version 2 of the Simple Network Management Protocol
        (SNMPv2)", RFC 1906, January 1996.

   [11] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message
        Processing and Dispatching for the Simple Network Management
        Protocol (SNMP)", RFC 2272, January 1998.

   [12] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM)
        for version 3 of the Simple Network Management Protocol
        (SNMPv3)", RFC 2274, January 1998.

   [13] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Protocol
        Operations for Version 2 of the Simple Network Management
        Protocol (SNMPv2)", RFC 1905, January 1996.

   [14] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC
        2273, January 1998.

   [15] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access
        Control Model (VACM) for the Simple Network Management Protocol
        (SNMP)", RFC 2275, January 1998.

   [16] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB
        using SMIv2", RFC 2233, November 1997.

   [17] Fowler D., "Definitions of Managed Objects for the DS1 and E1
        Interface Types", RFC 2495, January 1999.

   [18] Brown, T., and Tesink, K., "Definitions of Managed Objects for
        the SONET/SDH Interface Type", Work in Progress.

   [19] American National Standard for telecommunications - digital
        hierarchy - electrical interfaces, ANSI T1.102- 1987.

   [20] American National Standard for telecommunications - digital
        hierarchy - formats specification, ANSI T1.107- 1988.



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   [20a]ANSI T1.107a-1990.

   [21] American National Standard for telecommunications - Carrier-to-
        Customer Installation - DS3 Metallic Interface, ANSI T1.404-
        1989.

   [22] American National Standard for Telecommunications -- Layer 1 In-
        Service Digital Transmission Performance Monitoring T1.231, Sept
        1993.

   [23] CCITT - Digital Multiplex Equipment Operating at the Third Order
        Bit Rate of 34 368 Kbit/s and the Forth Order Bit Rate of 139
        264 Kbit/s and Using Positive Justification, G.751

   [24] European Telecommunications Standards Institute -- ETS "34M" --
        Metropolitan Area Network Physical Convergence Layer Procedure
        for 34.368 Megabits per Second, T/NA(91)18, May 1991.

   [25] Fowler, D., "Definitions of Managed Objects for the Ds0 and
        DS0Bundle Interface Types", RFC 2494, January 1999.

   [26] Tesink, K., "Textual Conventions for MIB Modules Using
        Performance History Based on 15 Minute Intervals", RFC 2493,
        January 1999.

9.  Security Considerations

   SNMPv1 by itself is such an insecure environment.  Even if the
   network itself is secure (for example by using IPSec), even then,
   there is no control as to who on the secure network is allowed to
   access and GET (read) the objects in this MIB.

   It is recommended that the implementors consider the security
   features as provided by the SNMPv3 framework.  Specifically, the use
   of the User-based Security Model RFC 2274 [12] and the View-based
   Access Control Model RFC 2275 [15] is recommended.

   It is then a customer/user responsibility to ensure that the SNMP
   entity giving access to an instance of this MIB, is properly
   configured to give access to those objects only to those principals
   (users) that have legitimate rights to access them.

   Setting any of the following objects to an inappropriate value can
   cause loss of traffic.  The definition of inappropriate varies for
   each object.  In the case of dsx3LineType, for example, both ends of
   a ds3/e3 must have the same value in order for traffic to flow.  In
   the case of dsx3SendCode and dsx3LoopbackConfig, for another example,
   traffic may stop transmitting when particular loopbacks are applied.



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      dsx3LineType
      dsx3LineCoding
      dsx3SendCode
      dsx3LoopbackConfig
      dsx3TransmitClockSource
      dsx3LineLength
      dsx3Channelization

   Setting the following object is mischevious, but not harmful to
   traffic
      dsx3CircuitIdentifier

   Setting the following object can cause an increase in the number of
   traps received by the network management station.
      dsx3LineStatusChangeTrabEnable

10.  Author's Address

   David Fowler
   Newbridge Networks
   600 March Road
   Kanata, Ontario, Canada K2K 2E6

   Phone: (613) 599-3600, ext 6559
   EMail: davef@newbridge.com


























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11.  Full Copyright Statement

   Copyright (C) The Internet Society (1999).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
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Fowler, Ed.                 Standards Track                    [Page 60]
^L