1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T V.150.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2003) SERIES V: DATA COMMUNICATION OVER THE TELEPHONE NETWORK Interworking with other networks Modem-over-IP networks: Procedures for the end-to-end connection of V-series DCEs ITU-T Recommendatio
2、n V.150.1 ITU-T V-SERIES RECOMMENDATIONS DATA COMMUNICATION OVER THE TELEPHONE NETWORK General V.1V.9 Interfaces and voiceband modems V.10V.34 Wideband modems V.35V.39 Error control V.40V.49 Transmission quality and maintenance V.50V.59 Simultaneous transmission of data and other signals V.60V.99 In
3、terworking with other networks V.100V.199 Interface layer specifications for data communication V.200V.249 Control procedures V.250V.299 Modems on digital circuits V.300V.399 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. V.150.1 (01/2003) i ITU-T Recommendation V
4、.150.1 Modem-over-IP networks: Procedures for the end-to-end connection of V-series DCEs Summary This Recommendation defines the inter-operation of two PSTN to IP network gateways that facilitate the end-to-end connection of V-series DCEs over an IP network. The principal characteristics of these ga
5、teways are: a mechanism to allow the transparent transport of modem signals end-to-end, a mechanism to allow the termination of modem signals at the gateways and the transport of the data between gateways, the definition of a transport protocol, which is suitable to relay data between gateways, and
6、procedures to allow gateways to transition between Voice-over-Internet Protocol and Modem-over-Internet Protocol operation. Source ITU-T Recommendation V.150.1 was approved on 13 January 2003 by ITU-T Study Group 16 (2001-2004) under the ITU-T Recommendation A.8 procedure. This edition includes the
7、modifications introduced by Corrigendum 1 approved on July 2003 and by Corrigendum 2 approved on March 2004. ii ITU-T Rec. V.150.1 (01/2003) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication
8、 Standardization Sector (ITU-T) 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 (WTS
9、A), which meets every four years, 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 w
10、ithin ITU-Ts purview, the necessary 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. Compliance with this Recom
11、mendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such
12、 as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommend
13、ation 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 the Recommendation development process. As of the date of approva
14、l of this Recommendation, ITU had 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 information and are therefore strongly urged to consult the TSB patent
15、database. ITU 2004 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. V.150.1 (01/2003) iii CONTENTS Page 1 Scope 1 1.1 Recommendation version . 1 2 References. 1 3 Definitions and abbreviations. 3 3.1
16、Definitions 3 3.2 Abbreviations . 4 4 Conventions 6 5 Introduction 6 5.1 Compliance requirements. 7 6 Modem-over-IP gateway functions 7 7 Audio mode 8 8 Voiceband data mode . 8 8.1 Selection of VBD voice codecs and other enhanced functionality 9 8.2 Minimum requirements for VBD . 9 9 Modem relay mod
17、e. 9 9.1 Universal-modem relay gateway type 9 9.2 V.8-modem relay gateway type 10 10 Operational modes of MoIP . 10 11 Modem relay PHY layer functions. 11 12 Modem relay error control functions 12 12.1 Error control configurations . 12 12.2 Error-controlled PSTN links. 14 12.3 Non-error-controlled P
18、STN links. 14 12.4 Break handling 16 13 Modem relay trans-compression functions. 17 13.1 No Trans-Compression (N-TCX). 17 13.2 Single Trans-Compression (S-TCX) 18 13.3 Double Trans-Compression (D-TCX) 18 13.4 Mixed-function operation. 19 13.5 Hierarchy for interoperability. 19 13.6 XID/LR profiles f
19、or use in modem relay connection scenario MR1 . 20 14 Modem relay data transfer 21 14.1 Data type definitions. 21 14.2 Support of DLCI. 21 14.3 General statement on the use of start-stop characters 21 14.4 Selection of data types 21 14.5 Mandatory modem relay data types . 21 iv ITU-T Rec. V.150.1 (0
20、1/2003) Page 14.6 Optional modem relay data types. 22 14.7 Gateway-to-gateway control channel functionality and interfaces 22 15 Modem-over-IP functionality and interfaces 23 15.1 Gateway-to-gateway protocol definitions and procedures. 23 15.2 Gateway capability and call set-up messages. 23 15.3 Gat
21、eway call discrimination messages. 26 15.4 Modem relay status messages 29 16 Start-up mode of operation . 45 17 Facsimile interworking requirements . 45 18 Text telephony interworking requirements. 45 19 Call set up procedures. 45 20 Call discrimination procedures. 45 20.1 V.25 calling tone, V.8 CI
22、processing and bell-type modem answer tone 46 20.2 V.8 bis processing 46 20.3 Call discrimination procedure/answer tone treatment selection. 46 20.4 Answer tone processing 46 20.5 Modem-over-IP mode selection procedures. 48 20.6 CM-JM procedures for determining MoIP mode. 49 20.7 JM delay procedure
23、50 20.8 Call discrimination SDL diagrams . 51 21 Procedures for audio to MoIP transport switching. 64 22 Procedures for modem relay operation. 64 22.1 Procedures used for gateway to DCE error control 64 22.2 Compression negotiation procedures . 67 22.3 Data transfer phase . 75 23 Modem delay procedu
24、res 75 23.1 Initial start up 75 23.2 Retrain and rate renegotiations. 76 24 Cleardown procedures 76 25 IP transport . 77 25.1 SPRT packet structure for MoIP 77 25.2 MoIP content header. 78 Annex A ASN.1 notation 78 Annex B Simple Packet Relay Transport (SPRT) protocol 78 B.1 Overview 78 B.2 SPRT tra
25、nsport protocol specification 79 Annex C State signalling events protocol. 83 C.1 Introduction 83 ITU-T Rec. V.150.1 (01/2003) v Page C.2 Definition of media states. 83 C.3 RTP packet format for state signalling events 84 C.4 Reliability . 87 C.5 State signalling event definitions 90 Annex D Procedu
26、res for voiceband data only mode of operation 93 Annex E SDP description of sessions supporting SPRT-based modem relay 93 E.0 Abbreviations . 93 E.1 Introduction 94 E.2 Optional information 98 E.3 Examples of complete SDP descriptors . 103 Annex F Definition of capabilities for use within H.245-base
27、d systems 104 F.1 Scope 104 F.2 Introduction 104 F.3 Modem over IP (MoIP) capability identification and exchange 104 F.4 MoIP capability definition syntax 105 F.5 Explanation of V150MoIPCapability elements 106 F.6 SSE capability identification and exchange . 107 Appendix I Connection scenarios . 108
28、 I.1 Voice Band data (VBD) mode . 108 I.2 Modem relay connection scenario MR1. 109 I.3 Modem relay connection scenario MR2. 109 I.4 Modem relay connection scenario MR3. 109 I.5 Modem relay connection scenario MR4. 110 Appendix II Call discrimination call flows. 110 II.1 Scope 110 II.2 Answer tone tr
29、eatment 110 II.3 Call discrimination . 111 Appendix III Call discrimination call flows suitable for use with facsimile-over-IP. 114 Appendix IV Call discrimination call flows suitable for use for text-over-IP 115 Appendix V Summary of DCE signals used during call discrimination 117 V.1 Definition of
30、 answer DCE generated signals to be considered for discrimination. 117 V.2 Definition of calling DCE generated signals to be considered for discrimination. 118 Appendix VI Descriptions of non-V-series modes of operation. 120 VI.1 Bell 103 mode of operation 120 VI.2 Bell 212A mode of operation . 120
31、VI.3 TIA/EIA-825 mode of operation 121 VI.4 MNP5 mode of operation . 121 vi ITU-T Rec. V.150.1 (01/2003) Page Appendix VII Gateway implementation guide . 121 VII.1 Scope 121 VII.2 VBD 121 VII.3 Rate control for configurations using SPRT channel 1 121 VII.4 XID/LR profiles 123 Appendix VIII Bibliogra
32、phy. 126 ITU-T Rec. V.150.1 (01/2003) 1 ITU-T Recommendation V.150.1 Modem-over-IP networks: Procedures for the end-to-end connection of V-series DCEs 1 Scope This Recommendation specifies the operation between two IP network gateways to facilitate the end-to-end connection of V-series DCEs over an
33、IP network. The gateways are specified herein in terms of their functionality, signals and messages and operating procedures. The principal characteristics of these gateways are as follows: a) Support of a mechanism to allow the transparent transport of modem signals end-to-end. b) Support of mechan
34、isms to allow the termination of modem signals at the gateways and the transport of the data between gateways. c) The definition of a transport protocol, which can be used to relay the data between gateways. d) The definition of procedures to allow gateways to transition between Voice-over-Internet
35、Protocol and Modem-over-Internet Protocol operation. This Recommendation includes mandatory requirements, recommendations and options; these are designated by the words “shall,“ “should,“ and “may“ respectively. 1.1 Recommendation version For the purposes of forward and backward compatibility, this
36、Recommendation is assigned a version number. The usage and definition of this version number is defined in ITU-T Rec. V.150.0. Version: 1 NOTE The reader is encouraged to check on the ITU-T website for any normative or informative amendments to this Recommendation. 2 References The following ITU-T R
37、ecommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation ar
38、e therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as
39、a stand-alone document, the status of a Recommendation. ITU-T Recommendation G.711 (1988), Pulse Code Modulation (PCM) of voice frequencies. ITU-T Recommendation H.245 (2003), Control protocol for multimedia communication. ITU-T Recommendation H.248 (2000), Gateway control protocol. ITU-T Recommenda
40、tion H.323, Annex P (2003), Transfer of modem signals over H.323. ITU-T Recommendation T.38 (2002), Procedures for real-time Group 3 facsimile communication over IP networks. 2 ITU-T Rec. V.150.1 (01/2003) ITU-T Recommendation V.8 (2000), Procedures for starting sessions of data transmission over th
41、e public switched telephone network. ITU-T Recommendation V.8 bis (2000), Procedures for the identification and selection of common modes of operation between data circuit-terminating equipments (DCEs) and between data terminal equipments (DTEs) over the public switched telephone network and on leas
42、ed point-to-point telephone-type circuits. ITU-T Recommendation V.14 (1993), Transmission of start-stop characters over synchronous bearer channels. ITU-T Recommendation V.17 (1991), A 2-wire modem for facsimile applications with rates up to 14 400 bit/s. ITU-T Recommendation V.18 (2000), Operationa
43、l and interworking requirements for DCEs operating in the text telephone mode. ITU-T Recommendation V.21 (1988), 300 bits per second duplex modem standardized for use in the general switched telephone network. ITU-T Recommendation V.22 bis (1988), 2400 bits per second duplex modem using the frequenc
44、y division technique standardized for use on the general switched telephone network and on point-to-point 2-wire leased telephone-type circuits. ITU-T Recommendation V.23 (1988), 600/1200-baud modem standardized for use in the general switched telephone network. ITU-T Recommendation V.24 (2000), Lis
45、t of definitions for interchange circuits between data terminal equipment (DTE) and data circuit-terminating equipment (DCE). ITU-T Recommendation V.25 (1996), Automatic answering equipment and general procedures for automatic calling equipment on the general switched telephone network including pro
46、cedures for disabling of echo control devices for both manually and automatically established calls. ITU-T Recommendation V.26 bis (1988), 2400/1200 bits per second modem standardized for use in the general switched telephone network. ITU-T Recommendation V.26 ter (1988), 2400 bits per second duplex
47、 modem using the echo cancellation technique standardized for use in the general switched telephone network and on point-to-point 2-wire leased telephone-type circuits. ITU-T Recommendation V.27 ter (1988), 4800/2400 bits per second modem standardized for use in the general switched telephone networ
48、k. ITU-T Recommendation V.29 (1988), 9600 bits per second modem standardized for use on point-to-point 4-wire leased telephone-type circuits. ITU-T Recommendation V.32 bis (1991), A duplex modem operating at data signalling rates of up to 14 400 bit/s for use on the general switched telephone networ
49、k and on leased point-to-point 2-wire telephone-type circuits. ITU-T Recommendation V.34 (1998), A modem operating at data signalling rates of up to 33 600 bit/s for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits. ITU-T Recommendation V.42 (2002), Error-correcting procedures for DCEs using asynchronous-to-synchronous conversion. ITU-T Recommendation V.42 bis (1990), Data compression procedures for data circuit- terminating equipment (DCE) using err
