1、 International Telecommunication Union ITU-T V.150.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 2(05/2006) 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 Amendmen
2、t 2: ToIP and new SPRT data types support ITU-T Recommendation V.150.1 (2003) Amendment 2 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 main
3、tenance V.50V.59 Simultaneous transmission of data and other signals V.60V.99 Interworking 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
4、 of ITU-T Recommendations. ITU-T Rec. V.150.1 (2003)/Amd.2 (05/2006) i ITU-T Recommendation V.150.1 Modem-over-IP networks: Procedures for the end-to-end connection of V-series DCEs Amendment 2 ToIP and new SPRT data types support Summary This Recommendation defines the inter-operation of two PSTN t
5、o IP network gateways that facilitate the end-to-end connection of V-series DCEs over an IP network. The principal characteristics of these gateways 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
6、and the transport of the data between gateways, the definition of a transport protocol, which is suitable to relay data between gateways, and procedures to allow gateways to transition between Voice-over-Internet Protocol and Modem-over-Internet Protocol operation. Amendment 1 added new code definit
7、ions to the SSE Protocol Reason Identifier Codes (RIC) contained in Table 12/V.150.1, which are intended to support the SSE protocol in ITU-T Rec. V.152 and the Text Relay. Amendment 2 adds support to the Text-over-IP procedures defined in ITU-T Rec. V.151 and to new SPRT data types. Source Amendmen
8、t 2 to ITU-T Recommendation V.150.1 (2003) was approved on 29 May 2006 by ITU-T Study Group 16 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. V.150.1 (2003)/Amd.2 (05/2006) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in t
9、he field of telecommunications. The ITU Telecommunication 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.
10、The World Telecommunication Standardization Assembly (WTSA), 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 Resolutio
11、n 1. In some areas of information technology which fall within 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
12、a recognized operating agency. Compliance with this Recommendation 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.
13、The words “shall“ or some other obligatory language such 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 possibili
14、ty 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 the Recom
15、mendation development process. As of the date of approval 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
16、 are therefore strongly urged to consult the TSB patent database. ITU 2006 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 (2003)/Amd.2 (05/2006) iii CONTENTS Page 1) Clause 2 References 1 2)
17、 Clause 3.2 Abbreviations 1 3) Clause 10 Operational modes of MoIP. 2 4) Clause 15.3 Gateway call discrimination messages . 4 5) Clause 15.4 Modem relay status messages. 4 6) 15.4.1 Initialization message (INIT). 4 7) Clause 15.4.5 CONNECT message 5 8) New clauses 15.4.11.8, 15.4.11.9 and 15.4.11.10
18、 6 9) Clause 16 Start-up mode of operation 7 10) Clause 17 7 11) Clause 18 8 12) Clause C.2.5 Text Relay (TR) 8 13) Clause C.5.2 List of state signalling events 9 14) Clause C.5.3 SSE protocol operation . 9 15) Clause C.5.5 SSE reason identifier codes. 9 16) Annex D 9 17) Appendix IV . 10 ITU-T Rec.
19、 V.150.1 (2003)/Amd.2 (05/2006) 1 ITU-T Recommendation V.150.1 Modem-over-IP networks: Procedures for the end-to-end connection of V-series DCEs Amendment 2 ToIP and new SPRT data types support Modifications introduced by this amendment are shown in revision marks. Unchanged text is replaced by elli
20、psis (). Some parts of unchanged texts (clause numbers, etc.) have been kept to indicate the correct insertion points. 1) Clause 2 References Add the following new references ITU-T Recommendation V.92 (2000), Enhancements to Recommendation V.90. ITU-T Recommendation V.151 (2006), Procedures for end-
21、to-end connection of analogue PSTN text telephones over an IP network utilizing text relay. ITU-T Recommendation V.152 (2005), Procedures for supporting voice-band data over IP networks. ITU-T Recommendation T.38 (2005), Procedures for real-time Group 3 facsimile communication over IP networks. ITU-
22、T Recommendation X.680 (2002) | ISO/IEC 8824-1:2002, Information technology Abstract Syntax Notation One (ASN.1): Specification of basic notation. 2) Clause 3.2 Abbreviations Add the following new abbreviations alphabetically. ToIP Text over Internet Protocol TR Text Relay 2 ITU-T Rec. V.150.1 (2003
23、)/Amd.2 (05/2006) 3) Clause 10 Operational modes of MoIP Modifiy the following clause and Figure 4 as follows: Other modes of operation that may be optionally provided by MoIP gateways are Fax over IP (FoIP) and Text over IP (ToIP). The procedures for FoIP are defined in ITU-T Rec. T.38. Procedures
24、for ToIP are defined in ITU-T Rec. V.151. Procedures for ToIP are beyond the scope of this Recommendation. The transitions between MoIP and FoIP/ToIP using the SSE protocol are for further study. Figure 4 illustrates the relationship between these defined modes. At any given time, a MoIP gateway sha
25、ll be either in or in transition to one of these modes. ITU-T Rec. V.150.1 (2003)/Amd.2 (05/2006) 3 V.150.1_F04Audio modeVoicebanddataModem relayFax over IPorText over IPFigure 4/V.150.1 MoIP operational modes and transition state 4 ITU-T Rec. V.150.1 (2003)/Amd.2 (05/2006) 4) Clause 15.3 Gateway ca
26、ll discrimination messages Modify Table 11 as follows: Table 11/V.150.1 Call discrimination messages Title Transport channel Event codes (decimal) Functional description of message content Comments Fax Relay SSE (Note) 4 Switch to FoIP Procedures for this media switch are for further study Text Rela
27、y SSE (Note) 5 Switch to ToIPText Relay Procedures used for this media switch are defined in ITU-T Rec. V.151are for further study Text Probe SSE (Note) 6 Switch to Text Probe state Procedures used for this media switch are defined in ITU-T Rec. V.151 NOTE The SSE protocol is defined in Annex C. The
28、 Event codes are defined also in the same annex. 5) Clause 15.4 Modem relay status messages Modify Table 16 as follows: Table 16/V.150.1 List of modem relay messages Message Name Message ID (decimal) TransportChannel Description I_FRAME 21 1 or 3 Framed Data (optional) I_OCTET-CS 22 1 or 3 Octet wit
29、h sequence number (Optional) I_CHAR-STAT-CS 23 1 or 3 Character with static and sequence number (Optional) I_CHAR-DYN-CS 24 1 or 3 Character with dynamic and sequence number (Optional) Reserved 2225-99 N/A Reserved for use by ITU-T VENDOR 100-127 N/A Vendor specific messages 6) 15.4.1 Initialization
30、 message (INIT) Modify Table 17 as follows: ITU-T Rec. V.150.1 (2003)/Amd.2 (05/2006) 5 Table 17/V.150.1 INIT definitions INIT bits MSB:LSB Definition 4:15 Optional MoIP Data types. This field indicates the optional data types that are supported by the gateways receiver. Support is indicated by a va
31、lue of binary ONE in the appropriate bit position. A binary ZERO indicates no support. b4: I_RAW-BIT support b5: I_FRAME support b6: I_CHAR-STAT support b7: I_CHAR-DYN support b8: I_OCTET-CS support b9: I_CHAR-STAT-CS support b10: I_CHAR-DYN-CS support b118b15: Reserved for ITU-T; these bits are set
32、 to zero by the transmitter and not interpreted by the receiver. 7) Clause 15.4.5 CONNECT message Modify Table 25 as follows: Table 25/V.150.1 CONNECT definitions CONNECT bits MSB:LSB Definition 49:63 Available Data Types: This field indicates the data types available for use by the peer gateway. b4
33、9: Octet without format with no DLCI. Indication of this data type is only valid for the symmetrical non-error configuration. b50: I_RAW-BIT b51: I_FRAME b52: I_CHAR-STAT b53: I_CHAR-DYN b54: I_OCTET-CS b55: I_CHAR-STAT-CS b56: I_CHAR-DYN-CS b574b63: Reserved for ITU-T; these bits are set to zero by
34、 the transmitter and not interpreted by the receiver. 6 ITU-T Rec. V.150.1 (2003)/Amd.2 (05/2006) 8) New clauses 15.4.11.8, 15.4.11.9 and 15.4.11.10 Add the following new clauses 15.4.11.8 Octet with sequence number (I_OCTET-CS) The format of this data type message is given in Figure 20a. r msgID CS
35、 Octets Figure 20a/V.150.1 Octet with sequence number In this message: r is a 1-bit field reserved for future use by the ITU-T. Message senders shall set this field to 0. Message receivers shall ignore the value of this field. MsgID is a 7-bit field whose value identifies the message; unique values
36、are assigned to the octet compressed raw data message and the bit compressed raw data message. CS Character sequence number. This two-byte field is initialized to zero upon establishment of SPRT connection. CS is incremented by one after each character is transmitted into the IP network (modulo 6553
37、6). The sequence number in the SPRT packet represents the sequence number for the first character in the SPRT packet payload. Octets is a sequence of octet user-data. This data type is the same as Octet without formatting (I-Octet) but with an additional sequence number field. The CS field provides
38、a character sequence number that can be used by the MoIP application to generate the correct number of fill characters when there is packet loss detected in the IP network. 15.4.11.9 Character with static and sequence number (I_CHAR-STAT-CS) The format of this data type message is given in Figure 20
39、b. r msgID r D P S CS Data in octet format Figure 20b/V.150.1 Character with static and sequence number format In this message: r is a 1-bit field reserved for future use by the ITU-T. Message senders shall set this field to 0. Message receivers shall ignore the value of this field. MsgID is a 7-bit
40、 field whose value identifies the message; a unique value is assigned to the I_CHAR data type. CS Character sequence number. This two-byte field is initialized to zero upon establishment of SPRT connection. CS is incremented by one after each character is transmitted into the IP network (modulo 6553
41、6). The sequence number in the SPRT packet represents the sequence number for the first character in the SPRT packet payload. D is a 2-bit field indicating the number of data bits: 0-5 bits; 1-6 bits; 2-7 bits; 3-8 bits. ITU-T Rec. V.150.1 (2003)/Amd.2 (05/2006) 7 P is a 3-bit field indicating the p
42、arity type: 0 unknown; 1 none; 2 even parity; 3 odd parity; 4 space parity; 5 mark parity; 6 reserved; 7 reserved. S is a 2-bit field indicating the number of stop bits: 0-1 stop bit; 1-2 stop bits; 2 reserved; 3 reserved. Octets is an integer number of octets representing start-stop characters. Thi
43、s data type is the same as Character with Static format (I_CHAR-STAT) with an additional character sequence field. The CS field provides a character sequence number that can be used by the MoIP application to generate the correct number of fill characters when there is packet loss detected in the IP
44、 network. 15.4.11.10 Character with dynamic and sequence number (I_CHAR-DYN-CS) The format of this data type message is the same as for Character with Static and sequence number format. This data type allows a change of format. The character format may be changed dynamically during a MR session. The
45、 CS field provides a character sequence number that can be used by the MoIP application to generate the correct number of fill characters when there is packet loss detected in the IP network. 15.4.12 Vendor-specific messages (VENDOR) 9) Clause 16 Start-up mode of operation Modifiy Table 31 as follow
46、s: Table 31/V.150.1 MoIP initial modes Additional supported modes by MoIP gateway Facsimile-over-IP (T.38) and/or Text-over-IP (V.151) Voice-over-IP Start as No No Modem-over-IP No Yes Voice-over-IP Yes No Modem-over-IP Yes Yes Voice-over-IP 10) Clause 17 Modify Clause 17 as follows: 17 Facsimile in
47、terworking requirements The support and interworking of FoIP gateways with MoIP gateways is for further study. The support and interworking of FoIP Gateways with MoIP Gateways is defined in Annex F/T.38. 8 ITU-T Rec. V.150.1 (2003)/Amd.2 (05/2006) 11) Clause 18 Modify Clause 18 as follows: 18 Text t
48、elephony interworking requirements The support and interworking of ToIP gateways with MoIP gateways is for further study. Methods and procedures for the support of PSTN text telephones is defined in ITU-T Rec. V.151 for Text Relay and ITU-T Rec. V.152 for VBD. For gateways that implement both this R
49、ecommendation and ITU-T Rec. V.151, the following needs to be considered. Firstly, since the default media switching methods for this Recommendation and ITU-T Rec. V.151 are different, it is required that Gateways that support both mechanisms shall consider the use of the SSE protocol in the V.151 procedures to be required in order to allow for correct interoperation. In general, and with the exception of three cases, the application of the V.151 discrimination procedures for the detect
