rfc2885.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                                          F. Cuervo
Request for Comments: 2885                                     N. Greene
Category: Standards Track                                Nortel Networks
                                                              C. Huitema
                                                   Microsoft Corporation
                                                               A. Rayhan
                                                         Nortel Networks
                                                                B. Rosen
                                                                 Marconi
                                                               J. Segers
                                                     Lucent Technologies
                                                             August 2000


                      Megaco Protocol version 0.8

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 document is common text with Recommendation H.248 as
   redetermined in Geneva, February 2000.  It must be read in
   conjunction with the Megaco Errata, RFC 2886.  A merged document
   presenting the Megaco protocol with the Errata incorporated will be
   available shortly.

   The protocol presented in this document meets the requirements for a
   media gateway control protocol as presented in RFC 2805.













Cuervo, et al.              Standards Track                     [Page 1]

RFC 2885                    Megaco Protocol                  August 2000


TABLE OF CONTENTS

   1. SCOPE..........................................................6
   2. REFERENCES.....................................................6
   2.1 Normative references..........................................6
   2.2 Informative references........................................8
   3. DEFINITIONS....................................................9
   4. ABBREVIATIONS.................................................10
   5. CONVENTIONS...................................................11
   6. CONNECTION MODEL..............................................11
   6.1 Contexts.....................................................14
        6.1.1 Context Attributes and Descriptors....................15
        6.1.2 Creating, Deleting and Modifying Contexts.............15
   6.2 Terminations.................................................15
        6.2.1 Termination Dynamics..................................16
        6.2.2 TerminationIDs........................................17
        6.2.3 Packages..............................................17
        6.2.4 Termination Properties and Descriptors................18
        6.2.5 Root Termination......................................20
   7. COMMANDS......................................................20
   7.1 Descriptors..................................................21
        7.1.1 Specifying Parameters.................................21
        7.1.2 Modem Descriptor......................................22
        7.1.3 Multiplex Descriptor..................................22
        7.1.4 Media Descriptor......................................23
        7.1.5 Termination State Descriptor..........................23
        7.1.6 Stream Descriptor.....................................24
        7.1.7 LocalControl Descriptor...............................24
        7.1.8 Local and Remote Descriptors..........................25
        7.1.9 Events Descriptor.....................................28
        7.1.10 EventBuffer Descriptor...............................31
        7.1.11 Signals Descriptor...................................31
        7.1.12 Audit Descriptor.....................................32
        7.1.13 ServiceChange Descriptor.............................33
        7.1.14 DigitMap Descriptor..................................33
        7.1.15 Statistics Descriptor................................38
        7.1.16 Packages Descriptor..................................39
        7.1.17 ObservedEvents Descriptor............................39
        7.1.18  Topology Descriptor.................................39
   7.2 Command Application Programming Interface....................42
        7.2.1 Add...................................................43
        7.2.2 Modify................................................44
        7.2.3 Subtract..............................................45
        7.2.4 Move..................................................46
        7.2.5 AuditValue............................................47
        7.2.6 AuditCapabilities.....................................48
        7.2.7 Notify................................................49
        7.2.8 ServiceChange.........................................50



Cuervo, et al.              Standards Track                     [Page 2]

RFC 2885                    Megaco Protocol                  August 2000


        7.2.9 Manipulating and Auditing Context Attributes..........54
        7.2.10 Generic Command Syntax...............................54
   7.3 Command Error Codes..........................................55
   8. TRANSACTIONS..................................................56
   8.1 Common Parameters............................................58
        8.1.1 Transaction Identifiers...............................58
        8.1.2 Context Identifiers...................................58
   8.2 Transaction Application Programming Interface................58
        8.2.1 TransactionRequest....................................59
        8.2.2 TransactionReply......................................59
        8.2.3 TransactionPending....................................60
   8.3 Messages.....................................................61
   9. TRANSPORT.....................................................61
   9.1 Ordering of Commands.........................................62
   9.2 Protection against Restart Avalanche.........................63
   10. SECURITY CONSIDERATIONS......................................64
   10.1 Protection of Protocol Connections..........................64
   10.2 Interim AH scheme...........................................65
   10.3 Protection of Media Connections.............................66
   11.  MG-MGC CONTROL INTERFACE....................................66
   11.1 Multiple Virtual MGs........................................67
   11.2 Cold Start..................................................68
   11.3 Negotiation of Protocol Version.............................68
   11.4 Failure of an MG............................................69
   11.5 Failure of an MGC...........................................69
   12. PACKAGE DEFINITION...........................................70
   12.1 Guidelines for defining packages............................71
        12.1.1 Package..............................................71
        12.1.2 Properties...........................................72
        12.1.3 Events...............................................72
        12.1.4 Signals..............................................73
        12.1.5 Statistics...........................................73
        12.1.6 Procedures...........................................73
   12.2 Guidelines to defining Properties, Statistics and Parameters
        to Events and Signals.......................................73
   12.3 Lists.......................................................74
   12.4 Identifiers.................................................74
   12.5 Package Registration........................................74
   13.  IANA CONSIDERATIONS.........................................74
   13.1 Packages....................................................74
   13.2 Error Codes.................................................75
   13.3 ServiceChange Reasons.......................................76
   ANNEX A: BINARY ENCODING OF THE PROTOCOL (NORMATIVE).............77
   A.1 Coding of wildcards..........................................77
   A.2 ASN.1 syntax specification...................................78
   A.3 Digit maps and path names....................................94
   ANNEX B TEXT ENCODING OF THE PROTOCOL (NORMATIVE)................95
   B.1 Coding of wildcards..........................................95



Cuervo, et al.              Standards Track                     [Page 3]

RFC 2885                    Megaco Protocol                  August 2000


   B.2 ABNF specification...........................................95
   ANNEX C TAGS FOR MEDIA STREAM PROPERTIES (NORMATIVE)............107
   C.1 General Media Attributes....................................107
   C.2 Mux Properties..............................................108
   C.3 General bearer properties...................................109
   C.4 General ATM properties......................................109
   C.5 Frame Relay.................................................112
   C.6 IP..........................................................113
   C.7 ATM AAL2....................................................113
   C.8 ATM AAL1....................................................114
   C.9 Bearer Capabilities.........................................116
   C.10 AAL5 Properties............................................123
   C.11 SDP Equivalents............................................124
   C.12 H.245......................................................124
   ANNEX D TRANSPORT OVER IP (NORMATIVE)...........................125
   D.1 Transport over IP/UDP using Application Level Framing.......125
        D.1.1 Providing At-Most-Once Functionality.................125
        D.1.2 Transaction identifiers and three-way handshake......126
                D.1.2.1 Transaction identifiers....................126
                D.1.2.2 Three-way handshake........................126
        D.1.3 Computing retransmission timers......................127
        D.1.4 Provisional responses................................128
        D.1.5 Repeating Requests, Responses and Acknowledgements...128
   D.2  using TCP..................................................130
           D.2.1 Providing the At-Most-Once functionality..........130
           D.2.2 Transaction identifiers and three way handshake...130
           D.2.3 Computing retransmission timers...................131
           D.2.4 Provisional responses.............................131
           D.2.5 Ordering of commands..............................131
   ANNEX E BASIC PACKAGES..........................................131
   E.1 Generic.....................................................131
        E.1.1 Properties...........................................132
        E.1.2 Events...............................................132
        E.1.3 Signals..............................................133
        E.1.4 Statistics...........................................133
   E.2 Base Root Package...........................................133
        E.2.1 Properties...........................................134
        E.2.2 Events...............................................135
        E.2.3 Signals..............................................135
        E.2.4 Statistics...........................................135
        E.2.5 Procedures...........................................135
   E.3 Tone Generator Package......................................135
        E.3.1 Properties...........................................135
        E.3.2 Events...............................................136
        E.3.3 Signals..............................................136
        E.3.4 Statistics...........................................136
        E.3.5 Procedures...........................................136
   E.4 Tone Detection Package......................................137



Cuervo, et al.              Standards Track                     [Page 4]

RFC 2885                    Megaco Protocol                  August 2000


        E.4.1 Properties...........................................137
        E.4.2 Events...............................................137
        E.4.3 Signals..............................................139
        E.4.4 Statistics...........................................139
        E.4.5 Procedures...........................................139
   E.5 Basic DTMF Generator Package................................140
        E.5.1 Properties...........................................140
        E.5.2 Events...............................................140
        E.5.3 Signals..............................................140
        E.5.4 Statistics...........................................141
        E.5.5 Procedures...........................................141
   E.6 DTMF detection Package......................................141
        E.6.1 Properties...........................................142
        E.6.2 Events...............................................142
        E.6.3 Signals..............................................143
        E.6.4 Statistics...........................................143
        E.6.5 Procedures...........................................143
   E.7 Call Progress Tones Generator Package.......................143
        E.7.1 Properties...........................................144
        E.7.2 Events...............................................144
        E.7.3 Signals..............................................144
        E.7.4 Statistics...........................................145
        E.7.5 Procedures...........................................145
   E.8 Call Progress Tones Detection Package.......................145
        E.8.1 Properties...........................................145
        E.8.2 Events...............................................145
        E.8.3 Signals..............................................145
        E.8.4 Statistics...........................................145
        E.8.5 Procedures...........................................146
   E.9 Analog Line Supervision Package.............................146
        E.9.1 Properties...........................................146
        E.9.2 Events...............................................146
        E.9.3 Signals..............................................147
        E.9.4 Statistics...........................................148
        E.9.5 Procedures...........................................148
   E.10 Basic Continuity Package...................................148
        E.10.1 Properties..........................................148
        E.10.2 Events..............................................148
        E.10.3 Signals.............................................149
        E.10.4 Statistics..........................................150
        E.10.5 Procedures..........................................150
   E.11 Network Package............................................150
        E.11.1 Properties..........................................150
        E.11.2 Events..............................................151
        E.11.3 Signals.............................................152
        E.11.4 Statistics..........................................152
        E.11.5 Procedures..........................................153
   E.12 RTP  Package...............................................153



Cuervo, et al.              Standards Track                     [Page 5]

RFC 2885                    Megaco Protocol                  August 2000


        E.12.1 Properties..........................................153
        E.12.2 Events..............................................153