rfc3020.txt

最新的RFC

Network Working Group                                            P. Pate
Request for Comments: 3020                                      B. Lynch
Category: Standards Track                              Overture Networks
                                                              K. Rehbehn
                                                   Megisto Systems, Inc.
                                                           December 2000


                     Definitions of Managed Objects
                   for Monitoring and Controlling the
                 UNI/NNI Multilink Frame Relay Function

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 (2000).  All Rights Reserved.

Abstract

   This memo defines a Management Information Base (MIB) for monitoring
   and controlling a UNI/NNI Multilink Frame Relay Function as defined
   in Frame Relay Forum FRF.16.  This MIB also includes conformance and
   notification information.

Table of Contents

   1 The SNMP Management Framework ................................    2
   2 Overview .....................................................    3
   2.1 Multilink Frame Relay Background ...........................    3
   2.1.1 Terminology ..............................................    4
   2.1.2 Reference Model ..........................................    5
   2.2 Structure of the MIB .......................................    5
   2.2.1 mfrBundleMaxNumBundles ...................................    6
   2.2.2 mfrBundleNextIndex .......................................    6
   2.2.3 mfrBundleTable ...........................................    6
   2.2.4 Bundle-to-ifIndex Mapping Table ..........................    6
   2.2.5 mfrBundleLinkTable .......................................    6
   2.3 Relationship With Other MIBS and Tables ....................    7
   2.3.1 Relationship With Interface Table ........................    7
   2.3.1.1 Bundle Links ...........................................    7
   2.3.1.2 Bundles ................................................    7



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   2.3.1.3 Mapping Between ifIndex and mfrBundleIndex .............    8
   2.3.1.4 ifTable Objects ........................................    8
   2.3.2 Relationship With Interface Stack Table ..................    9
   2.3.3 Relationship With Frame Relay DTE MIB ....................    9
   2.3.4 Relationship With Frame Relay Service MIB ................    9
   2.3.5 Example ..................................................    9
   2.4 Creation Of Bundles and Bundle Links .......................   11
   2.4.1 Creation Of Bundles ......................................   11
   2.4.2 Creation Of Bundle Links .................................   11
   2.5 Notifications ..............................................   11
   2.5.1 Bundle ...................................................   11
   2.5.1.1 linkUp .................................................   12
   2.5.1.2 linkDown ...............................................   12
   2.5.2 Bundle Link ..............................................   12
   2.5.2.1 linkUp .................................................   12
   2.5.2.2 linkDown ...............................................   12
   2.5.2.3 mfrMibTrapBundleLinkMismatch ...........................   12
   3 Object Definitions ...........................................   13
   4 Acknowledgments ..............................................   32
   5 References ...................................................   32
   6 Security Considerations ......................................   34
   7 Authors' Addresses ...........................................   35
   8 Full Copyright Statement .....................................   36

1.  The SNMP Management Framework

   The SNMP Management Framework presently consists of five major
   components:

   o  An overall architecture, described in RFC 2571 [RFC2571].

   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 [RFC1155], STD 16, RFC 1212 [RFC1212] and RFC 1215
      [RFC1215].  The second version, called SMIv2, is described in STD
      58: RFC 2578 [RFC2578], RFC 2579 [RFC2579] and RFC 2580 [RFC2580].

   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 [RFC1157].  A second version of the
      SNMP message protocol, which is not an Internet standards track
      protocol, is called SNMPv2c and described in RFC 1901 [RFC1901]
      and RFC 1906 [RFC1906].  The third version of the message protocol
      is called SNMPv3 and described in RFC 1906 [RFC1906], RFC 2572
      [RFC2572] and RFC 2574 [RFC2574].





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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 [RFC1157].  A second set of protocol
      operations and associated PDU formats is described in RFC 1905
      [RFC1905].

   o  A set of fundamental applications described in RFC 2573 [RFC2573]
      and the view-based access control mechanism described in RFC 2575
      [RFC2575].

   A more detailed introduction to the current SNMP Management Framework
   can be found in RFC 2570 [RFC2570].

   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.

2.  Overview

   This document defines a Management Information Base (MIB) for
   monitoring and controlling the UNI/NNI Multilink Frame Relay
   function.  The agreement on which this MIB is based was defined and
   documented by the Frame Relay Forum in the Frame Relay Forum Document
   FRF.16 [FRF.16].

2.1.  Multilink Frame Relay Background

   Multilink Frame Relay (MFR) for the User-to-Network Interface (UNI)
   and the Network-to-Network Interface (NNI) provides physical
   interface emulation for frame relay devices.  The emulated physical
   interface consists of one or more physical links, called "bundle
   links", aggregated together into a single "bundle" of bandwidth.
   This service provides a frame-based inverse multiplexing function,
   sometimes referred to as an "IMUX".







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   The bundle provides the same order-preserving service as a physical
   layer for frames sent on a data link connection.  In addition, the
   bundle provides support for all Frame Relay services based on UNI and
   NNI standards.

2.1.1.  Terminology

   Physical Link --    A single physical interface that interconnects
                       two devices in a frame relay network (e.g., DS1,
                       DS0, Bearer channel, refer to FRF.14).

   Bundle --           A grouping of one or more physical links using
                       the formats and procedures of multilink frame
                       relay.  The bundle operates as a logical
                       interface function that emulates a single
                       physical interface to the Q.922 data link layer.

   Bundle Link --      A MFR sub-component that controls operation of
                       one of the bundle's physical links.
































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2.1.2.  Reference Model

+--------------------------+               +--------------------------+
|   Switching Layer -OR-   |               |   Switching Layer -OR-   |
| Higher-Level Applications|               | Higher-Level Applications|
+--------------------------+               +--------------------------+
|          |C-Plane - Q.933|               |          |C-Plane - Q.933|
| U-Plane  |    (Note 1)   |               | U-Plane  |    (Note 1)   |
| (Note 3) |---------------|               | (Note 3) |---------------|
|          |Q.922 (Note 2) |               |          |Q.922 (Note 2) |
+--------------------------+               +--------------------------+
| Data Link Layer (Q.922)  |               | Data Link Layer (Q.922)  |
+--------------------------+               +--------------------------+
|       Bundle (B)         |               |       Bundle (B)         |
+--------------------------+               +--------------------------+
| Bundle | Bundle | Bundle |               | Bundle | Bundle | Bundle |
|  Link  |  Link  |  Link  |               |  Link  |  Link  |  Link  |
|  (BL)  |  (BL)  |  (BL)  |               |  (BL)  |  (BL)  |  (BL)  |
+--------+--------+--------+               +--------+--------+--------+
|Physical|Physical|Physical|               |Physical|Physical|Physical|
|  (PH)  |  (PH)  |  (PH)  |  __________   |  (PH)  |  (PH)  |  (PH)  |
+----+---+----+---+----+---+ /\          \ +----+---+----+---+----+---+
     |        |        |    /  \          \      |        |        |
     |        |        +--------\          \-----+        |        |
     |        |           /      \          \             |        |
     |        +-------------------\          \------------+        |
     |           _________\_______/  Bundle  /_                    |
     |          /\               /          /  \                   |
     +------------| Bundle Link /          /    |------------------+
                \/_____________/          /____/
                             \/__________/

                   Figure 1: MFR Reference Diagram


   Note 1: C-Plane operation as described in Q.933 [Q.933] and FRF.4
   [FRF.4]

   Note 2: Multiple frame acknowledged information transfer mode as
   described in Q.922 [Q.922]

   Note 3: Core aspects for use with frame relay bearer service as
   described in Q.922, Annex A [Q.922]

2.2.  Structure of the MIB

   The UNI/NNI MFR managed objects consist of two scalar objects and
   three tables.



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2.2.1.  mfrBundleMaxNumBundles

   This scalar is used to inform the manager of the maximum number of
   bundles supported by this device.

2.2.2.  mfrBundleNextIndex

   This scalar is used to assist the manager in selecting a value for
   mfrBundleIndex during row creation.  It can also be used to avoid
   race conditions with multiple managers trying to create rows in the
   table (see RFC 2494 [RFC2494] for one such algorithm).

2.2.3.  mfrBundleTable

   This table provides a means to configure and monitor bundles.  It is
   indexed by mfrBundleIndex and contains these columns:

      -  mfrBundleIndex                    Integer32
      -  mfrBundleIfIndex                  InterfaceIndex
      -  mfrBundleRowStatus                RowStatus
      -  mfrBundleNearEndName              SnmpAdminString
      -  mfrBundleFragmentation            INTEGER
      -  mfrBundleMaxFragSize              Integer32
      -  mfrBundleTimerHello               INTEGER
      -  mfrBundleTimerAck                 INTEGER
      -  mfrBundleCountMaxRetry            INTEGER
      -  mfrBundleActivationClass          INTEGER
      -  mfrBundleThreshold                Integer32
      -  mfrBundleMaxDiffDelay             Integer32
      -  mfrBundleSeqNumSize               INTEGER
      -  mfrBundleLinksConfigured          Integer32
      -  mfrBundleLinksActive              Integer32
      -  mfrBundleBandwidth                Integer32
      -  mfrBundleFarEndName               SnmpAdminString
      -  mfrBundleResequencingErrors       Counter32

2.2.4.  Bundle-to-ifIndex Mapping Table

   This table provides a means to take an ifIndex and find the
   corresponding mfrBundleIndex.  It is indexed by ifIndex and contains
   these columns:

      -  mfrBundleIfIndexMapping           Integer32

2.2.5.  mfrBundleLinkTable

   This table provides a means to configure and monitor bundle links.
   It is indexed by ifIndex and contains these columns:



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      -  mfrBundleLinkRowStatus             RowStatus
      -  mfrBundleLinkConfigBundleIndex     Integer32
      -  mfrBundleLinkNearEndName           SnmpAdminString
      -  mfrBundleLinkState                 MfrBundleLinkState
      -  mfrBundleLinkFarEndName            SnmpAdminString
      -  mfrBundleLinkFarEndBundleName      SnmpAdminString
      -  mfrBundleLinkDelay                 Integer32
      -  mfrBundleLinkFramesControlTx       Counter32
      -  mfrBundleLinkFramesControlRx       Counter32
      -  mfrBundleLinkFramesControlInvalid  Counter32
      -  mfrBundleLinkTimerExpiredCount     Counter32
      -  mfrBundleLinkLoopbackSuspected     Counter32
      -  mfrBundleLinkUnexpectedSequence    Counter32
      -  mfrBundleLinkMismatch              Counter32

2.3.  Relationship With Other MIBS and Tables

2.3.1.  Relationship With Interface Table

2.3.1.1.  Bundle Links

   Each bundle link will appear as an interface in the ifTable.  The
   ifIndex that appears in the ifTable is used for indexing the bundle
   link tables in the UNI-NNI MFR MIB.

2.3.1.2.  Bundles

   Each bundle will appear as an interface in the ifTable.  There will
   be corresponding mfrBundleIndex which may be different than the
   ifIndex of the bundle.

   The reason is best summarized in RFC 2494 [RFC2494], which describes
   frame relay bundle of DS0.  It says:

      This table is not indexed by ifIndex because the manager has to
      choose the index in a createable row and the agent must be allowed
      to select ifIndex values.

   The rows in the ifEntry table are not createable as they do not have
   row status.  RFC 2863 [RFC2863] suggests that the ifIndex should be
   chosen by the agent.  Here is its statement regarding row creation
   and deletion: