1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T G.965 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2001) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital sections and digital line system Digital section and digital transmission systems for customer access to ISDN V-
2、interfaces at the digital local exchange (LE) V5.2 interface (based on 2048 kbit/s) for the support of access network (AN) ITU-T Recommendation G.965 (Formerly CCITT Recommendation) ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CO
3、NNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELA
4、Y OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TESTING EQUIPMENTS G.500G.599 TRANSMISSION MEDIA CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIG
5、ITAL LINE SYSTEM G.900G.999 General G.900G.909 Parameters for optical fibre cable systems G.910G.919 Digital sections at hierarchical bit rates based on a bit rate of 2048 kbit/s G.920G.929 Digital line transmission systems on cable at non-hierarchical bit rates G.930G.939 Digital line systems provi
6、ded by FDM transmission bearers G.940G.949 Digital line systems G.950G.959 Digital section and digital transmission systems for customer access to ISDN G.960G.969 Optical fibre submarine cable systems G.970G.979 Optical line systems for local and access networks G.980G.989 Access networks G.990G.999
7、 For further details, please refer to the list of ITU-T Recommendations. ITU-T G.965 (03/2001) i ITU-T Recommendation G.965 V-interfaces at the digital local exchange (LE) V5.2 interface (based on 2048 kbit/s) for the support of access network (AN) Summary This Recommendation defines a V-interface (
8、V5.2) for the connection of an Access Network (AN) and the Local Exchange (LE) for the support of the following access types analogue telephone access; ISDN basic access with an NT1 separate from the AN, or integrated in the AN, based on ITU-T G.960 and I.430; ISDN primary rate access with an NT1 se
9、parate from the AN, or integrated in the AN, based on ITU-T G.962 and I.431; other analogue or digital accesses for semi-permanent connections without associated outband signalling information, with flexible information channel (bearer channel) allocation by use of a bearer channel connection protoc
10、ol providing concentration capability within the AN. This Recommendation is based on ITU-T G.964 and refers to it for those parts which are common in both Recommendations. The electrical and functional interface specification for the interface links uses the 2048 kbit/s parts of ITU-T G.703, G.704 a
11、nd G.706. Up to 16 interface links may be operated in parallel forming the V5.2 interface. The signalling from the PSTN user port is converted into a stimulus protocol with a functional part for the signalling path using layer 3 multiplexing for the information from the different user ports. The inf
12、ormation from the ISDN D-channels is frame relayed in the Access Network using the mechanisms defined in ITU-T Q.933. A control protocol defined in this Recommendation is used for the exchange of the individual port status and control functions required for the coordination with the call control pro
13、cedures in the Local Exchange. A bearer channel connection protocol establishes and de-establishes bearer connections required on demand, identified by the signalling information, under the control of the Local Exchange. A link control protocol is defined for the mult-link management to control link
14、 identification, link blocking and link failure conditions. In order to coordinate the traffic demands in the various protocols, up to three communication channels can be provisioned per interface link to transport the various protocols and frame relayed information. The data link layer for the prot
15、ocols is defined on the bases of ITU-T Q.920 and Q.921. A protection protocol, operated on two separate data links for security reasons, is defined to manage the protection switching of communication channels in case of link failures. Source ITU-T Recommendation G.965 was revised by ITU-T Study Grou
16、p 15 (2001-2004) and approved under the WTSA Resolution 1 procedure on 1 March 2001. ii ITU-T G.965 (03/2001) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T)
17、 is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four year
18、s, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the neces
19、sary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the p
20、ossibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of t
21、he Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest inf
22、ormation and are therefore strongly urged to consult the TSB patent database. ITU 2002 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from ITU. I
23、TU-T G.965 (03/2001) iii CONTENTS Page 1 Scope. 1 2 Normative references 2 3 Definitions, symbols and abbreviations 3 3.1 Definitions 3 3.2 Symbols and abbreviations . 4 4 Electrical and physical interface requirements . 5 5 Procedural interface requirements 5 5.1 Link control requirements and proce
24、dures . 5 5.1.1 Link-ID verification. 6 5.1.2 Link blocking. 6 6 Services and architecture aspects and requirements . 6 6.1 On-demand services 6 6.1.1 PSTN . 6 6.1.2 ISDN Basic Access (ISDN-BA) 6 6.1.3 ISDN Primary Rate Access (ISDN-PRA) . 6 6.2 Permanent Line (PL) capability 7 6.3 Semi-permanent le
25、ased line 8 6.4 Permanent leased line service . 8 7 Control and provisioning 8 7.1 Control principles . 8 7.1.1 General requirements and assumptions . 8 7.1.2 Control of ISDN-BA user port for the PL capability 9 7.1.3 Control of ISDN-PRA user ports when the PL capability is provided 9 7.2 Provisioni
26、ng strategy and requirements 11 7.2.1 General. 11 7.2.2 Provisioning requirements. 12 7.3 Bearer Channel Connection (BCC) 12 7.4 Protection 13 8 Protocol architecture and multiplexing structure 13 8.1 Functional description. 13 8.2 Protocol requirements for PSTN and ISDN . 13 8.3 Time slots 15 8.4 T
27、ime slot allocation for physical communication channels 15 8.4.1 Data types for V5.2 C-paths 16 iv ITU-T G.965 (03/2001) Page 8.4.2 Communication paths when PSTN is provided on a V5.2 interface . 17 8.4.3 Communication paths when ISDN is provided on a V5.2 interface . 17 8.5 Layer 2 sublayering and
28、multiplexing on communication channels 17 8.6 Layer 3 multiplexing. 17 8.7 Congestion control 17 8.7.1 Flow control end to end . 17 8.7.2 Congestion control on the V5.2 interface 17 8.7.3 Blocking of ISDN user ports at layer 2 . 17 8.7.4 Flow control using LAPV5-DL mechanisms 18 9 Envelope Function
29、sublayer of LAPV5 (LAPV5-EF) 18 10 Data Link sublayer of LAPV5 (LAPV5-DL) . 18 10.1 Frame structure for peer-to-peer communication . 18 10.2 Invalid frames . 18 10.3 Elements of procedures and formats of fields for data link sublayer peer-to-peer communication 18 10.3.1 Link address field format. 18
30、 10.3.2 Link address field variables. 18 10.3.3 Control field formats . 18 10.3.4 Control field parameters and associated state variables 18 10.3.5 Frame types 18 10.4 Definition of the peer-to-peer procedures of the data link sublayer . 18 11 AN frame relay sublayer. 19 12 Sublayer-to-sublayer comm
31、unication and mapping function. 19 13 General layer 3 protocol structures. 19 13.1 General 19 13.2 Information elements that appear in every message (header). 20 13.2.1 Protocol Discriminator information element. 20 13.2.2 Layer 3 Address information element . 21 13.2.3 Message Type information elem
32、ent 21 13.3 Other information elements 22 13.4 Protocol message functional definition and information content . 22 13.5 Codesets 22 14 PSTN signalling protocol specification and layer 3 multiplexing 22 15 Control requirements and protocol . 23 15.1 ISDN-BA user port status indication and control. 23
33、 15.2 PSTN user port status indication and control . 23 ITU-T G.965 (03/2001) v Page 15.3 ISDN primary rate user port status indication and control . 23 15.3.1 General aspects 23 15.3.2 Events and function elements relevant for the control of the state machines 24 15.3.3 ISDN-PRA user port FSMs, AN
34、(ISDN port) and LE (ISDN port) 26 15.3.4 Performance monitoring aspects . 33 15.4 Control protocol 34 15.4.1 Control protocol message definition and content 34 15.4.2 General message format and information element coding 35 15.4.3 State definition of the control protocol 36 15.4.4 Control protocol p
35、rocedures 36 15.4.5 Accelerated alignment of the port related protocol entities and FSMs . 36 15.5 V5.2-re-provisioning procedures 37 16 Link control requirements and protocol 37 16.1 2048 kbit/s layer 1 link maintenance requirements 38 16.1.1 Events and failure reports 38 16.1.2 Detection algorithm
36、 for events and signals . 39 16.1.3 V5.2-interface layer 1 link FSM 40 16.1.4 Requirements and procedures for the additional functions . 42 16.2 Link control requirements and procedures . 42 16.2.1 The link blocking and unblocking. 42 16.2.2 The link identification . 43 16.2.3 Events and function el
37、ements relevant for the control of the link state machines 44 16.2.4 Link control FSM, AN (link) and LE (link) 45 16.3 Link control protocol 51 16.3.1 Link control protocol message definition and content 51 16.3.2 Link control protocol information element definition, structure and coding 55 16.3.3 D
38、efinitions of the link control protocol states . 57 16.3.4 Link control protocol procedure 57 16.3.5 Handling of error conditions 58 16.3.6 Timers for the link control protocol 60 16.3.7 AN and LE side layer 3 protocol entity state tables 60 17 BCC protocol elements and procedures 60 17.1 General 60
39、 17.2 BCC protocol entity definition . 63 17.2.1 Definition of BCC protocol states . 63 17.2.2 Definition of BCC protocol primitives, messages and timers. 64 vi ITU-T G.965 (03/2001) Page 17.3 BCC protocol message definition and content . 64 17.3.1 ALLOCATION message. 65 17.3.2 ALLOCATION COMPLETE m
40、essage. 69 17.3.3 ALLOCATION REJECT message 69 17.3.4 DE-ALLOCATION message 69 17.3.5 DE-ALLOCATION COMPLETE message 70 17.3.6 DE-ALLOCATION REJECT message. 70 17.3.7 AUDIT message 71 17.3.8 AUDIT COMPLETE message 71 17.3.9 AN FAULT message . 72 17.3.10 AN FAULT ACKNOWLEDGE message. 73 17.3.11 PROTO
41、COL ERROR message . 73 17.4 BCC information element definition, structure and coding 74 17.4.1 BCC Reference Number information element 74 17.4.2 Other information elements. 75 17.5 Description of the BCC protocol and the BCC procedures 83 17.5.1 General. 84 17.5.2 Bearer channel allocation Normal p
42、rocedure . 84 17.5.3 Bearer channel allocation Exceptional procedures. 85 17.5.4 Bearer channel de-allocation Normal procedure 86 17.5.5 Bearer channel de-allocation Exceptional procedures 87 17.5.6 Audit procedure . 88 17.5.7 AN internal failure notification procedure 88 17.5.8 Handling of error co
43、nditions 89 17.6 List of system parameters (timers) 92 17.7 LE side and AN side state transition tables 93 18 Protection protocol specification 96 18.1 General 96 18.1.1 Introduction . 96 18.1.2 Provisioning of physical and logical C-channels 97 18.1.3 Separation of responsibilities. 98 18.1.4 Manag
44、ement of C-channel resources after failure. 99 18.1.5 Monitoring functions and detection of failures . 100 18.1.6 Functional model for the protection protocol 100 18.2 Other principles. 101 18.3 Protection protocol entity definition. 102 18.3.1 Definition of protection protocol states. 102 18.3.2 De
45、finition of protection protocol events 102 ITU-T G.965 (03/2001) vii Page 18.4 Protection protocol message definition and content. 105 18.4.1 SWITCH-OVER REQ message 106 18.4.2 SWITCH-OVER COM message. 106 18.4.3 OS-SWITCH-OVER COM message. 107 18.4.4 SWITCH-OVER ACK message 107 18.4.5 SWITCH-OVER R
46、EJECT message 108 18.4.6 PROTOCOL ERROR message . 108 18.4.7 RESET SN COM message 109 18.4.8 RESET SN ACK message. 109 18.5 Protection protocol information element definition, structure and coding. 110 18.5.1 Logical C-channel identification information element 110 18.5.2 Sequence-number information
47、 element. 111 18.5.3 Physical C-channel identification information element 111 18.5.4 Rejection Cause information element 112 18.5.5 Protocol Error Cause information element 112 18.6 Protection protocol procedures . 114 18.6.1 General. 114 18.6.2 Broadcast of protection protocol messages on the two
48、data links of the primary and secondary link . 115 18.6.3 Standard protection switch-over procedure initiated by LE-side 117 18.6.4 Dedicated protection switch-over procedure initiated by OS LE 118 18.6.5 Protection switch-over procedure requested by AN-side 119 18.6.6 Handling of error conditions 1
49、21 18.7 List of system parameters . 124 18.8 AN and LE side state tables 125 18.8.1 Protection protocol FSM in the AN. 125 18.8.2 Protection protocol FSM in the LE 126 Annex A Service scenarios, architecture and functional definition of access arrangements with AN at the LE 128 A.1 Conclusions on multiple V5-interface applications 128 A.2 Conclusions on architecture aspects . 128 A.3 Implementation of QAN. 129 A.4 Requirements for the support of the PL capability through an ISDN basic access 129 A.5 Requirements for the support of the PL capabilit
