rfc2494.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

Network Working Group                               D. Fowler, Editor
Request for Comments: 2494                         Newbridge Networks
Category: Standards Track                                January 1999


                     Definitions of Managed Objects
               for the DS0 and DS0 Bundle 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 DS0 and DS0
   Bundle interfaces.  This document is a companion document with
   Definitions of Managed Objects for the DS1/E1/DS2/E2 (RFC 2495 [17]),
   DS3/E3 (RFC 2496 [18]), 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
   2 Overview .....................................................    3
   2.1 BONDing Terminology ........................................    3
   2.2 Use of ifTable for DS0 Layer ...............................    3
   2.3 Using ifStackTable .........................................    4
   2.3.1 Usage of Channelization for DS3, DS1, DS0 ................    6
   2.3.2 Usage of ifIndex Mapping for DS0Bundle ...................    7
   3 Overview of the MIB ..........................................    7
   3.1 DS0 MIB ....................................................    8
   3.2 DS0Bundle MIB ..............................................    8
   4 Object Definitions for DS0 ...................................    8
   4.1 The DS0 Config Group .......................................    9



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   4.1.1 The DS0 Configuration Table ..............................    9
   4.1.2 The DS0 Channel Mapping Table ............................   12
   5 Object Definitions for DS0 Bundle ............................   15
   5.1 The DS0 Bundle Config Group ................................   15
   5.1.1 The DS0 Bundle Table .....................................   15
   5.2 The DS0 Bonding Group ......................................   18
   5.2.1 The DS0 Bonding Table ....................................   18
   6 Intellectual Property ........................................   21
   7 Acknowledgments ..............................................   22
   8 References ...................................................   22
   9 Security Considerations ......................................   23
   10 Author's Address ............................................   24
   11 Full Copyright Statement ....................................   25

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].

    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.



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        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.

2.  Overview

   These objects are used when the particular media being used to
   realize an interface is a DS0 interface.  At present, this applies to
   these values of the ifType variable in the Internet-standard MIB:

        ds0 (81)
        ds0Bundle (82)

2.1.  BONDing Terminology

   Please reference The BONDing Spec [20] for definitions of terms used
   to describe bonding modes.

2.2.  Use of ifTable for DS0 Layer

   The following items are defined in RFC 2233 [16].

   Only the ifGeneralInformationGroup and ifCounterDiscontinuityGroup
   need to be supported.

              ifTable Object           Use for DS0 Layer
   ======================================================================
              ifIndex                  Interface index.

              ifDescr                  See interfaces MIB [16].

              ifType                   ds0(81) or ds0Bundle(82).

              ifSpeed                  64000 for ds0 (regardless of the
                                       setting of robbed bit signalling)
                                       or N*64000 for ds0Bundle.

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



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              ifAdminStatus            See interfaces MIB [16].

              ifOperStatus             See interfaces MIB [16].

              ifLastChange             See interfaces MIB [16].

              ifName                   See interfaces MIB [16].

              ifLinkUpDownTrapEnable   Set to disabled(2).
                                       Supports read-only access.

              ifHighSpeed              Set to rounded ifSpeed/1000000.

              ifConnectorPresent       Set to false(2).

2.3.  Using ifStackTable

   This section describes by example how to use ifStackTable to
   represent the relationship of ds0 and ds0Bundles with ds1 interfaces.
   Implementors of the stack table for ds0 and ds0Bundle interfaces
   should look at the appropriate RFC for the service being stacked on
   ds0s and ds0Bundles.  Examples given below are for illustration
   purposes only.

   Example: A Frame Relay Service is being carried on 4 ds0s of a ds1.

           +---------------------+
           | Frame Relay Service |
           +---------------------+
                      |
           +---------------------+
           | ds0Bundle           |
           +---------------------+
             |     |     |     |
           +---+ +---+ +---+ +---+
           |ds0| |ds0| |ds0| |ds0|
           +---+ +---+ +---+ +---+
             |     |     |     |
           +---------------------+
           | ds1                 |
           +---------------------+

   The assignment of the index values could for example be:

           ifIndex  Description
           1        FrameRelayService (type 44)
           2        ds0Bundle         (type 82)
           3        ds0 #1            (type 81)



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           4        ds0 #2            (type 81)
           5        ds0 #3            (type 81)
           6        ds0 #4            (type 81)
           7        ds1               (type 18)

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

           ifStackTable Entries

           HigherLayer   LowerLayer
           0             1
           1             2
           2             3
           2             4
           2             5
           2             6
           3             7
           4             7
           5             7
           6             7
           7             0


   In the case where the frameRelayService is using a single ds0, then
   the ds0Bundle is not required.

           +---------------------+
           | Frame Relay Service |
           +---------------------+
             |
           +---+
           |ds0|
           +---+
             |
           +---------------------+
           | ds1                 |
           +---------------------+

   The assignment of the index values could for example be:

           ifIndex  Description
           1        FrameRelayService (type 44)
           2        ds0               (type 81)
           3        ds1               (type 18)

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



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           ifStackTable Entries

           HigherLayer   LowerLayer
           0             1
           1             2
           2             3
           3             0

2.3.1.  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.  Timeslot
   16 is not created for framing types that do not pass data over it.

   Assume that a DS3 (with ifIndex 1) is channelized into DS1s (without
   DS2s).  The object dsx3Channelization is set to enabledDs1.  There
   will be 28 DS1s in the ifTable.  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.  When this
   object is set to this value, 24 DS0s are created by the agent. There
   will be 24 DS0s in the ifTable for each DS1.  If the
   dsx1Channelization is set to disabled, the 24 DS0s are destroyed.

   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:










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           dsx0ChanMappingTable Entries

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

2.3.2.  Usage of ifIndex Mapping for DS0Bundle