rfc2496.txt

RFC 的详细文档！

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



Fowler, Ed.                 Standards Track                     [Page 1]

RFC 2496                      DS3/E3 MIB                    January 1999


   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].




Fowler, Ed.                 Standards Track                     [Page 2]

RFC 2496                      DS3/E3 MIB                    January 1999


    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




Fowler, Ed.                 Standards Track                     [Page 3]

RFC 2496                      DS3/E3 MIB                    January 1999


        (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].

















Fowler, Ed.                 Standards Track                     [Page 4]

RFC 2496                      DS3/E3 MIB                    January 1999


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



Fowler, Ed.                 Standards Track                     [Page 5]

RFC 2496                      DS3/E3 MIB                    January 1999


           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