rfc1595.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                                           T. Brown
Request for Comments: 1595                                     K. Tesink
Category: Standards Track                                        Editors
                                            Bell Communications Research
                                                              March 1994


                     Definitions of Managed Objects
                    for the SONET/SDH 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.

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in TCP/IP-based internets.
   In particular, it defines objects for managing Synchronous Optical
   Network/Synchronous Digital Hierarchy (SONET/SDH) objects.  This
   document is a companion document with Definitions of Managed Objects
   for the DS1/E1 and DS3/E3 Interface Types, RFC1406 [14] and RFC1407
   [13].

   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 SNMPv2 Network Management Framework ...............    2
   2. Objects ...............................................    3
   2.1 Format of Definitions ................................    3
   3. Overview ..............................................    4
   3.1 Use of the ifTable ...................................    4
   3.2 Use of ifTable for  SONET/SDH  Medium/Section/Line
       Layer ................................................    6
   3.3 Use of ifTable for SONET/SDH Paths. ..................    7
   3.4 Use of ifTable for SONET/SDH VTs/VCs .................    8
   3.5 SONET/SDH Terminology ................................    9
   3.6 Values for x for the Section, Line, Path,  and  VT
       Layers ...............................................   16
   4. Object Definitions ....................................   17
   4.1 The SONET/SDH Medium Group ...........................   18



AToM MIB Working Group                                          [Page 1]

RFC 1595                   SONET/SDH Objects                  March 1994


   4.2 The SONET/SDH Section Group ..........................   21
   4.2.1 The SONET/SDH Section Current Group ................   21
   4.2.2 The SONET/SDH Section Interval Group ...............   23
   4.3 The SONET/SDH Line Group .............................   25
   4.3.1 The SONET/SDH Line Current Group ...................   25
   4.3.2 The SONET/SDH Line Interval Group ..................   27
   4.4 The SONET/SDH Far End Line Group .....................   30
   4.4.1 The SONET/SDH Far End Line Current Group ...........   30
   4.4.2 The SONET/SDH Far End Line Interval Group ..........   32
   4.5 The SONET/SDH Path Group .............................   34
   4.5.1 The SONET/SDH Path Current Group ...................   34
   4.5.2 The SONET/SDH Path Interval Group ..................   37
   4.6 The SONET/SDH Far End Path Group .....................   39
   4.6.1 The SONET/SDH Far End Path Current Group ...........   39
   4.6.2 The SONET/SDH Far End Path Interval Group ..........   41
   4.7 The SONET/SDH Virtual Tributary Group ................   43
   4.7.1 The SONET/SDH VT Current Group .....................   43
   4.7.2 The SONET/SDH VT Interval Group ....................   46
   4.8 The SONET/SDH Far End VT Group .......................   48
   4.8.1 The SONET/SDH Far End VT Current Group .............   48
   4.8.2 The SONET/SDH Far End VT Interval Group ............   50
   4.9 Conformance Information ..............................   52
   4.10 Compliance Statements ...............................   52
   5. Acknowledgments .......................................   56
   6. References ............................................   57
   7. Security Considerations ...............................   59
   8. Authors' Addresses ....................................   59

1.  The SNMPv2 Network Management Framework

   The SNMPv2 Network Management Framework consists of four major
   components.  They are:

      RFC 1442 [1] which defines the SMI, the mechanisms used for
      describing and naming objects for the purpose of management.

      STD 17, RFC 1213 [6] defines MIB-II, the core set of managed
      objects for the Internet suite of protocols. Reference [12]
      defines the evolution of the Interfaces Group of MIB II in terms
      of extensions and precise applications of the objects.

      RFC 1445 [4] which defines the administrative and other
      architectural aspects of the framework.

      RFC 1448 [5] which defines the protocol used for network access to
      managed objects.





AToM MIB Working Group                                          [Page 2]

RFC 1595                   SONET/SDH Objects                  March 1994


   The Framework permits new objects to be defined for the purpose of
   experimentation and evaluation.

   This specification makes also use of:

      RFC 1443 [2] which defines textual conventions for the
      specification of managed objects.

      RFC 1444 [3] which defines conformance statements for the
      specification of managed objects.

2.  Objects

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the subset of Abstract Syntax Notation One (ASN.1) [7]
   defined in the SMI.  In particular, each object has a name, a syntax,
   and an encoding.  The name is an object identifier, an
   administratively assigned name, which specifies an object type.  The
   object type together with an object instance serves to uniquely
   identify a specific instantiation of the object.  For human
   convenience, we often use a textual string, termed the OBJECT
   DESCRIPTOR, to also refer to the object type.

   The syntax of an object type defines the abstract data structure
   corresponding to that object type.  The ASN.1 language is used for
   this purpose.  However, the SMI RFC 1442 purposely restricts the
   ASN.1 constructs which may be used.  These restrictions are
   explicitly made for simplicity.

   The encoding of an object type is simply how that object type is
   represented using the object type's syntax.  Implicitly tied to the
   notion of an object type's syntax and encoding is how the object type
   is represented when being transmitted on the network.  The SMI
   specifies the use of the basic encoding rules of ASN.1 [8], subject
   to the additional requirements imposed by the SNMP.

2.1.  Format of Definitions

   Section 4 contains contains the specification of all object types
   contained in this MIB module.  The object types are defined using the
   conventions defined in the SMI, as amended by the extensions
   specified in the SNMPv2 SMI.








AToM MIB Working Group                                          [Page 3]

RFC 1595                   SONET/SDH Objects                  March 1994


3.  Overview

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

               sonet (39), sonetPath (50), sonetVT (51)

   The definitions contained herein are based on the SONET/SDH
   specifications in ANSI T1.105 and T1.106-1988 [9, 9a, 10] and CCITT
   G.707, 708, 709, and G.783 [15-18].

3.1.  Use of the ifTable

   This section specifies how the MIB II interfaces group, as defined in
   [12], is used for SONET/SDH interfaces.  The SONET/SDH layers support
   several multiplexing possibilities.

   For example in SONET, an Synchronous Transport Signal 3 (STS-3) has 3
   SONET Paths, and a STS-3c has 1 SONET Path. Another example could be
   a STS-12 having 4 SONET STS-3c Paths.  Similarly, a SONET Synchronous
   Payload Envelope (SPE) can carry many Virtual Tributaries (VTs), for
   example, one SONET SPE can carry 28 VT1.5s.  It is important to note
   that an SPE and a VT in SONET is collectively referred to as a
   Virtual Container (VC) in SDH.  Also, an STS is called Synchronous
   Transport Module (STM) in SDH.

   Not all SONET/SDH equipment terminate all SONET/SDH layers.  For
   example, an SONET/SDH STE regenerator terminates SONET/SDH Sections
   only, and is transparent for all layers above that.  SONET/SDH Add-
   Drop multiplexers and Digital Cross Connect Systems terminate
   SONET/SDH Lines. SONET/SDH Terminal Multiplexers may also terminate
   SONET/SDH Paths and VTs/VCs.

   MIB II [6], as extended by [12], accommodates these cases by
   appropriate use of the MIB II system group, and the interfaces group.
   The system group can name and describe the type of managed resource.
   The interfaces group defines which SONET/SDH layers apply, how these
   layers are configured and multiplexed.  This is achieved by proper
   representation of SONET/SDH Layers by ifEntries as defined in [12],
   as follows:









AToM MIB Working Group                                          [Page 4]

RFC 1595                   SONET/SDH Objects                  March 1994


                        _____________________________
                       |             |          |    |  >
                       |             |          |    |  |
                       |    VT 1     |..........|VT K|   > K ifEntries
                       |             |          |    |  |
                       |_____________|__________|____|  >
                       |               |      |      |  >
                       |               |      |      |  |
                       |    Path 1     |......|Path L|   > L ifEntries
                       |               |      |      |  |
                       |_______________|______|______|  >
                       |                             |  >
                       |                             |  |
                       |    Line                     |  |
                       |                             |  |
                       |_____________________________|  |
                       |                             |  |
                       |                             |  |
                       |    Section Layer            |   > 1 ifEntry
                       |                             |  |
                       |_____________________________|  |
                       |                             |  |
                       |                             |  |
                       |    Physical Medium Layer    |  |
                       |                             |  |
                       |_____________________________|  >

                       Use of ifTable for a SONET/SDH port

   The exact configuration and multiplexing of the layers is maintained
   in the ifStackTable [12].




















AToM MIB Working Group                                          [Page 5]

RFC 1595                   SONET/SDH Objects                  March 1994


3.2.  Use of ifTable for SONET/SDH Medium/Section/Line Layer

   Only the ifGeneralGroup needs to be supported.

ifTable Object    Use for combined SONET/SDH Medium/Section/Line Layer
======================================================================
           ifIndex           Interface index.

           ifDescr           SONET/SDH Medium/Section/Line

           ifType            sonet(39)

           ifSpeed           Speed of line rate for SONET/SDH,
                             (e.g., 155520000 bps).

           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     Supports read-only access.
                             The desired administrative status of the
                             interface.

           ifOperStatus      The value testing(3) is not used.
                             This object assumes the value down(2),
                             if the objects sonetSectionCurrentStatus
                             and sonetLineCurrentStatus have
                             any other value than sonetSectionNoDefect(1)
                             and sonetLineNoDefect(1), respectively.

           ifLastChange      sysUpTime at the last change in
                             ifOperStatus.

           ifName            Textual name of the interface or an
                             OCTET STRING of zero length.

           ifLinkUpDownTrapEnable   Set to enabled(1).
                                    Supports read-only access.

           ifHighSpeed       Speed of line in Mega-bits per second
                             (e.g., 155 Mbps)

           ifConnectorPresent Set to true(1).