1、- STD= ITU-T RECMN V.253-ENGL 1998 INTERNATIONAL ITU=T Y862591 0650b31 TELECOMMUNICATION TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TO7 UNION V.253 SERIES V: DATA COMMUNICATION OVER THE TELEPHONE NETWORK Control procedures (02198) Control of voice-related functions in a DCE by an asynchronous D
2、TE ITU-T Recommendation V.253 (Previously CCITT Recommendation) ITU-T V-SERIES RECOMMENDATIONS DATA COMMUNICATION OVER THE TELEPHONE NETWORK General Interfaces and voiceband modems Wideband modems Error control Transmission quality and maintenance Simultaneous transmission of data and other signals
3、Interworking with other networks v.l-v.9 V. 1 O-V.34 v.35-v.39 V.40-V.49 V.50-V.59 V.60-V.99 v. 100-v. I99 Interface layer specifications for data communication V.200-V.249 Contr Il For further details, please refer to ITU-T List of Recommendations. ITU-T RECOMMENDATION V.253 CONTROL OF VOICE-RELATE
4、D FUNCTIONS IN A DCE BY AN ASYNCHRONOUS DTE Summary This Recommendation builds upon and extends the Asynchronous DCE “AT“ command set defined in Recommendation V.250. It describes a DCE command and response syntax for voice playback and record, for generation and detection of DTMF and other tones, a
5、s well as a syntax for switching between data mode, facsimile mode, and other future modes of operation. The additional mechanisms defined in this Recommendation allow a DTE in combination with a V.253-equipped DCE to implement Telephone Answering Device functions, optional speakerphone functions, a
6、nd to switch to appropriate data, facsimile, or other modes of operation depending on the type of the incoming call. Source ITU-T Recommendation V.253 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 6th of February 1998. STD-ITU-T RE
7、CMN V.253-ENGL 1998 YBb259L Ob50b34 7Lb FOREWORD IT (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (IT-T) is a permanent organ of the ITU. The ITU-T is responsible for studying tech
8、nical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups whic
9、h, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a c
10、ollaborative basis with IS0 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 The ITU draws attention to the possibility that the practice o
11、r implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The IT takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by JTU members or others outside of the Recommendation developme
12、nt process. As of the date of approval of this Recommendation, the 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 information and are theref
13、ore strongly urged to consult the TSB patent database. O IT 1998 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 the ITU. Recommendation V.25
14、3 (02198) 11 STD-ITU-T RECMN V-253-ENGL 1998 W 4862591 0650635 652 CONTENTS Page 1 2 3 4 4.1 5 5.1 5.2 5.3 5.4 5.5 6 6.1 6.2 6.3 6.4 Scope References Definitions Voice states and operation of a voice-capable DCE . Non-speakerphone section of a voice DCE 4.1.1 Voice states . 4.2.1 Voice states . Voic
15、e and network signalling support Events (reports sent to the DTE) Actions (commands sent to the DCE) Call discrimination . 5.3,l Description and definitions . 5.3.2 Hook control under voice Timing marks in the voice data stre am . Compression method and availability of event detection . Operation Nu
16、meric radix . Format conventions 6.2.1 Numbering conventions 6.2.2 6.2.3 Code word mapping conventions Command structure 6.3.1 AT commands . 6.3.2 Basic command syntax 6.3.3 Extended command syntax 6.3.4 Issuing commands . 6.3.5 Command execution 6.3.6 6.3.7 Session management 6.4.1 Scope . 6.4.2 Fl
17、ow control 6.4.3 6.4.4 Order of bit transmission . DCE responses from AT commands . Data stream transparent commands ( shielded event codes sent to the DTE Minimum event reporting requirements . DTMF event report sequence . Recorded DTMF tone on playback Silence detection during voice receives Actio
18、ns Simple action commands Configuration setting and initiating action commands . codes sent to the DCE . 8.3.1 Adjusting the volume and gain levels by codes . 8.3.2 Pause and resume commands during voice states with DTE to DCE data transfers . Support commands . Action commands . 9.1.1 Dial command
19、in voice (with +FCLASS=8.0) . 9.1.2 Hangup comrnand in voice (with +FCLASS=8) . 9.1.3 Repeat Caller ID (+VRID) Configuration commands . 9.2.1 Mode selection 9.2.2 +FCLASS=? 9.2.3 Caller Id service 9.2.4 DID service . 9.2.5 Automatic hangup control . Miscellaneous AT commands 9.3.1 S-parameters- . 9.
20、3.2 ATZ . Voice commands 1 O . 1 Action commands . Page 25 25 26 26 26 26 28 28 32 33 33 34 35 35 35 35 39 39 40 40 40 41 41 42 42 43 43 46 47 48 48 48 48 48 iv Recommendation V.253 (02198) . - STD-ITU-T RECMN V-253-ENGL 1998 4862591 0650637 425 - 10.2 10.3 10.4 10.5 . 1 O . 1.1 Initialize voice par
21、ameters . 10.1.2 Ring local phone 1 O . 1.3 Voice receive state . 10.1.4 Voice duplex state . 1 O . 1.5 DTMF and tone generation in voice . 1 O . 1.6 Transmit data state Action controls (configuration command) . 10.2.1 Receive gain selection . 10.2.2 Volume selection . 1 0.2.3 DTEDCE inactivity time
22、r 10.2.4 Analogue sourcedestination selection Ringing tone goes away timer . Ringing tone never appeared timer . Silence detection (QUIET and SILENCE) 10.2.8 Compression method selection Beep tone duration timer . Response controls (configuration commands) . Distinctive ring (ring cadence reporting)
23、 Control tone cadence reporting . DTEDCE interface (configuration commands) . 10.4.1 Buffer threshold setting . 10.4.2 Voice packet protocol Select DTEDCE interface rate (turn off automatic rate detection) Speakerphone commands . 10.5.1 Voice speakerphone state 10.2.5 10.2.6 10.2.7 10.2.9 10.3.1 10.
24、3.2 1 0.4.3 10.5.2 Microphone gain . 10.5.3 Speaker gain 10.5.4 Train acoustic echo-canceller 10.5.5 Train line echo-canceller . 10.5.6 Speakerphone duplex mode 10.5.7 +VEM= Annex A . Interworking with existing voice DTE Appendix I . 1.1 1.2 1.3 1.4 Suggested compression method and sample rate selec
25、tion Recording a welcome message . Answer the phone, play the greeting message and record a message Play back the welcome message . Page 48 48 50 51 53 56 57 57 57 58 58 61 61 62 63 66 67 67 70 71 71 71 72 73 73 76 77 .77 77 77 78 78 80 80 81 82 82 Recommendation V.253 (02/98) V STD.ITU-T RECMN V-25
26、3-ENGL 1998 4862591 Ob50638 361 1.5 1.6 1.7 1.8 Answer the phone. record a message and receive a facsimile Answer the phone and determine it is a facsimile Answer the phone and execute a facsimile protocol Answer the phone and execute a data handshake . Appendix II 11.1 Projected DTEDCE interface ra
27、tes at different sampling rates . 11.2 Common analog sourceldestination hardware configurations Appendix III . North American network documents Page 84 85 86 88 89 89 90 91 vi Recommendation V.253 (02/98) . STD-ITU-T RECMN V-253-ENGL 3998 4862593 O650639 2T8 Recommendation V.253 CONTROL OF VOICE-REL
28、ATED FUNCTIONS IN A DCE BY AN ASYNCHRONOUS DTE (Geneva, 1998) 1 Scope This Recommendation builds upon and extends the current Asynchronous DCE control Recommendation V.250 (ex-V.25 ter), to include a voice control and response interface definition, a collection of basic primitive functions that allo
29、ws the DTE to implement a call discrimination algorithm, and a simplified general control structure, which would include data, facsimile, voice, and other future modes as personalities. In particular, this Recommendation: o describes a DCE command and response syntax for voice playback and record, g
30、eneration and detection of DTMF and other tones, and a syntax to switch to facsimile, data modes, and other future modes. Optional Speakerphone operations are also included; o addresses the playing and recording of voice data; does not describe the call discrimination algorithm; mandates that at lea
31、st one of the voice compression algorithms listed in Table 17 be o describes compression method identifications; o o supported. NOTE - The transmission of duplex voice on the DTE interface is for further study. At the time of the adoption of this Recommendation, no agreement exists regarding the opt
32、imal call discrimination algorithm, or even whether a single algorithm is possible. In particular, there is question of the proper processing load distribution of the call discrimination operation - whether the DCE should contain the entire algorithm, or whether the DTE and DCE must share the effort
33、. This Recommendation requires the DTE and DCE to share the call discrimination effort, since the actual algorithm is unknown and a DCE only solution may entail unacceptable DCE storage requirements. This Recommendation assumes that the DTE and DCE are connected via a serial asynchronous connection
34、using V.24 circuits, and facilitates the use of serial ports by including and extending the T.32 Packet Protocol as an optional enhancement. The actual DTEDCE command and data interchange may be implemented in any environment that provides a octet serial bi-directional data stream, including, but no
35、t limited to - processor bus attached “Fax Boards“, local area networks, etc. The adaptation of the DTE/DCE command and data interchange contained in this Recommendation to these alternative communication schemes is beyond the scope of this Recommendation. 2 References The following ITU-T Recommenda
36、tions 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; all users of this Recommendation are the
37、refore 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. Recommendation V.253 (02/98) 1 CCITT Recommendation G.7 1 1 (1 988), Pulse Code M
38、odulation (PCM) of voice equencies. ITU-T Recommendation G.723.1 (1996), Speech coders: Dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3 kbit/s. CCITT Recommendation G.726 (1990), 40, 32, 24, 16 kbit/s Adaptive DzfSerential Pulse Code Modulation (ADPCM). CCITT Recomme
39、ndation G.728 (1992), Coding of speech at I6 kbit/s using low-delay code excited linear prediction. ITU-T Recommendation G.729 Annex A (1 996), Reduced complexity 8 kbith CS-ACELP speech codec. ITU-T Recommendation T.3 1 (1 995), Asynchronous facsimile DCE control - Service Class 1. ITU-T Recommenda
40、tion T.32 (1 99.9, Asynchronous facsimile DCE control - Service Class 2. CCITT Recommendation T.50 (1 992), International Reference Alphabet (IRA) (formerly International Alphabet No. 5 or IAS), Information technology - 7-bit coded character setfor information interchange. CCITT Recommendation V.4 (
41、1 988), General structure of signals of International Alphabet No 5 code for character oriented data transmission over public telephone networks. ITU-T Recommendation V.8 bis (1 996), Procedures for identijcation and selection of common modes of operation between Data Circuit-terminating Equipments
42、(DCEs) and between Data Terminal Equipments (DTEs) over the general switched telephone network and on leased point-to-point telephone-type circuits. ITU-T Recommendation V. 18 (1996), Operational and interworking requirements for DCEs operating in the text telephone mode. ITU-T Recommendation V.24 (
43、1 996), List of definitions for interchange circuits between Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE) . ITU-T Recommendation V.25 bis (1 996), Synchronous and asynchronous automatic dialling procedures on switched networks. ITU-T Recommendation V.250 (ex-V.25 ter) (
44、1997), Serial asynchronous automatic dialling and control. IS0 21 11, Data communication - Basic mode control procedures - Code independent information transfer. ISOAEC 3309: 1993, Information technology - Telecommunications and information exchange between systems - High-level Data Link Control (HD
45、LC) procedures - Frame structure. Definitions This Recommendation defines the following terms. 3.1 Data Terminal Equipment (DTE): A DTE is any terminal or computer capable of providing commands and data to operate a DCE, facsimile DCE, or a voice DCE. In practice, a DTE is a computer of any size. 2
46、Recommendation V.253 (02/98) STD-ITU-T RECMN V-253-ENGL I1998 = 4862591 0650641 956 = 3.2 Data Circuit-terminating Equipment CE): A DCE is any device that connects a DTE to a communications network. This Recommendation focuses on DCEs that connect to the General Switched Telephone Network (GSTN). Th
47、is class of DCEs includes DCEs compatible with V-Series modem Recommendations, facsimile DCEs, and voice DCEs. 3.3 facsimile DCE: A facsimile DCE is a device that provides facsimile communication facilities between a DTE and a remote Group 3 facsimile station across the GSTN, using the procedures sp
48、ecified in Recommendation T.3 1 or T.32. 3.4 voice DCE: A voice DCE is a device that provides voice communication facilities between a DTE and a remote station (source or destination of analog signals) across the GSTN. The DCE may provide services for selecting one or more local devices (to the DCE)
49、, in conjunction or in isolation from the GSTN, as the analog signal source/destination. 3.5 voice mode (data and facsimile): The overall DCE mode of operation that performs voice functions by accepting +V prefixed commands (voice commands), and providing voice and call discrimination event reports to the DTE. See 6.4.1.1 for details about the scope and rules of use for the +V prefixed commands. 3.6 command state: The DCE is not operating in the Voice Mode, and is not communicating with a remote station making the DCE ready to accept commands. The DCE
