1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU DATA COMMUNICATION OVER THE TELEPHONE NETWORK V.130 (08/95) ISDN TERMINAL ADAPTOR FRAMEWORK ITU-T Recommendation V.130 (Previously ?CCIlT Recommendation?) ITU-T RECMN*V*L30 75 4862573 RbIJAqL8 T43 FOREWORD Th
2、e ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommen- dations on them with a view to standardizing telecommunications on a world
3、wide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by
4、 the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). ITU-T Recommendation V.130 was prepared by ITU-T Study Group 14 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 29th of August 1995. NOTES 1. telecommunication administration and a recognize
5、d operating agency. 2. follows: In this Recommendation, the expression “Administration” is used for conciseness to indicate both a The status of annexes and appendices attached to the Series V Recommendations should be interpreted as - - an annex to a Recommendation forms an integral part of the Rec
6、ommendation; an appendix to a Recommendation does not form part of the Recommendation and only provides some complementary explanation or information specific to that Recommendation. O ITU 1996 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means
7、, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 1 2 3 4 5 6 7 8 9 10 11 4862571 CONTENTS Scope and introduction . 1.1 Scope 1.2 Introduction References Definitions Abbreviations . Reference models 5.1 Functional reference model 5.2 Protoc
8、ol reference model 5.4 Call mapping model Connection establishment (Call control) 6.1 Auto-calling procedures 6.2 Multi-Use bearer service applications Rate adaptation protocol and parameter negotiation 7.2 In-band negotiation procedures TE2 - TA interface considerations . 8.1 Physical interfaces 8.
9、2 8.3 Embedded interfaces . Multi-protocol terminal adaptor . 10.1 Introduction 10.2 10.3 Combined modem and terminal adaptor . Management . 5.3 Interworking model 7.1 Out-of-band (Q.931) procedures Flow control and buffering . Adaptation to 3.1 kJ3z audio bearer (GSTN interworking) Terminal adaptor
10、 with codec Appendix I . Protocol model for a V.110 TA (asynchronous mode) . Page 1 1 1 1 3 3 3 4 6 8 9 9 9 10 11 12 12 13 13 13 13 14 15 15 15 16 17 17 Recommendation V.130 . (08/95) I ITU-T RECMN*V-L30 95 Y8b259L Ob08920 bTL SUMMARY This Recommendation provides information on the functions of a te
11、rminal adaptor from both the conceptual and practical points of view. The expression “Terminal Adaptor” is commonly used to refer to a stand-alone item of equipment (or alternatively a printed circuit card plugged into a terminal) that allows a non-ISDN terminal to be connected to an ISDN user-netwo
12、rk interface. Formally though, Terminal Adaptor (TA) is the name of one of the (conceptual) Functional Groups defined in Recommendation 1.41 1. The TA Functional Group contains functions that allow a TE2 (non-ISDN) terminal to use the services provided by an ISDN. The popular understanding of the te
13、rm TA is thus well aligned with the theoretical definition. This Recommendation coordinates information from other Recommendations, expands on topics only briefly discussed elsewhere, describes the relationship between Terminal Adaptors and Modems, and provides tutorial material, and guidance on fut
14、ure enhancements and applications. II Recommendation V.130 (OW95) Recommendation V.130 ISDN TERMINAL ADAPTOR FRAMEWORK (Geneva, 1995) 1 Scope and introduction 1.1 Scope The purpose of this ISDN Terminal Adaptor Framework Recommendation is to: a) b) c) d) provide tutorial material; e) coordinate info
15、rmation from other Recommendations; expand on topics only briefly discussed elsewhere; describe the relationship between Terminal Adaptors and Modems; provide guidance on future enhancements and applications. 1.2 Introduction Formally, the expression “Terminal Adaptor” (TA) refers to one of the (con
16、ceptual) Functional Groups defined in Recommendation 1.41 1. The TA is described in 3.4.4A.411 and contains functions that allow a TE2 (non-ISDN) terminal to use the services provided by an ISDN. However, the expression “Terminal Adaptor” is also used to refer to a stand-alone item of equipment (or
17、alternatively a printed circuit card plugged into a terminal) that allows a non-ISDN terminal to be connected to an ISDN user-network interface. Also, there already exist a number of Recommendations which describe terminal adaptors and terminal adaptation protocols that allow terminals conforming to
18、 V- or X-Series Recommendations to be connected to the ISDN. Certain material in these Recommendations is of more general application and is referred to in this Recommendation. This Recommendation examines in detail the functions of a terminal adaptor from both the conceptual and practical points of
19、 view. Clause 10 describes a particular type of TA which is a combination of TA and modem functions. It allows a V-Series DTE to be connected to the ISDN and use the 3.1 kHz audio bearer service to communicate with another V-Series DTE attached via a modem to the GSTN. This means that no network-pro
20、vided interworking function (modem pool) is required, only the digital-to-analogue conversion and signalling facilities that are already provided for telephony. 2 References The following Recommendations and other references contain provisions which, through reference in this text, constitute provis
21、ions 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 therefore encouraged to investigate the possibility of applying the most recent edition of the Recommenda
22、tions and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. CCITT Recommendation G.711(1988), Pulse code modulation (PCM) ofvoicefrequencies. ITU-T Recommendation H.244 (1995), Synchronized aggregation of ISDN B-channels. ITU-T Recommendation
23、1.231.9 (1993), Circuit mode 64 kbit;/s and 8 kHz structured multi-use bearer service category. ITU-T Recommendation 1.320 (1993), ISDN protocol reference model. ITU-T Recommendation 1.333 (1993), Terminal selection in ISDN. - - - - - Recommendation V.130 (OW95) 1 ITU-T RECMN*V.L30 75 D 4862571 Ob08
24、722 ir?ir D ITU-T Recommendation 1.41 1 (1993), ISDN user-network interfaces - Reference configurations. ITU-T Recommendation 1.430 (1993), Basic user-network interface - Luyer I speccation. ITU-T Recommendation 1.431 (1993), Primary rate user-network integace - Luyer I specification. ITU-T Recommen
25、dation 1.501 (1993), Service interworking. ITU-T Recommendation 1.5 15 (1993), Parameter exchange for ISDN interworking. ITU-T Recommendation 1.530 (1993) Network interworking between an ISDN and a Public Switched Telephone Network (PSTN). ITU-T Recommendation 4.931 (1993), Digital Subscriber Signal
26、ling System No. 1 (DSS I) - ISDN user-network interface layer 3 specification for basic call control. ITU-T Recommendations T.200-Series1), Programming communication interface for terminal equipment connected to ISDN. ITU-T Recommendation V.8 (1994), Procedures for starting sessions of data transmis
27、sion over the general switched telephone network. ITU-T Recommendation V. 10 (1993), Electrical characteristics for unbalanced double-current interchange circuits operating at data signalling rates nominally up to 100 kbit/s. ITU-T Recommendation V. 1 1 (1993), Electrical characteristics for balance
28、d double-current interchange circuits operating at data signalling rates up to IO Mbit/s. ITU-T Recommendation V. 14 1993), Transmission of start-stop characters over synchronous bearer channels. ITU-T Recommendation V.24 (1993) List of definitions for interchange circuits between Data Terminal Equi
29、pment (DTE) and Data Circuit-Teminating Equipment (DCE). CCITT Recommendation V.25 bis (1988), Automatic calling andor answering equipment on the General Switched Telephone Network (GSTN) using the 100-series interchange circuits. ITU-T Recommendation V.25 ter (1 993, Serial asynchronous automatic d
30、ialling and control. ITU-T Recommendation V.28 (1993), Electrical characteristics for unbalanced double-current interchange circuits. IT-T Recommendation V. 12 (1995), Electrical characteristics for balanced double-current interchange circuits for interfaces with data signalling rates up to 52 Mbit/
31、s. CCITT Recommendation V.42 bis (1988) Data compression procedures for Data Circuit-Terminating Equipment (DCE) using error correcting procedures. ITU-T Recommendation V.58 (1994), Management information model for V-Series DCEs. CCITT Recommendation V.110 (1.463) (1992), Support of data terminal eq
32、uipment with V-Series type interfaces by an integrated services digital network. CCITT Recommendation V.120 (1.465) (1992), Support by an ISDN of data terminal equipment with V-Series type interfaces with provision for statistical multiplexing. CCIT Recommendation X.24 (1988), List of definitions fo
33、r interchange circuits between Data Terminal Equipment (DTE) and Data Circuit-Terminating Equipment (DCE) on public data networks. ITU-T Recommendation X.25 (1993), Interface between Data Terminal Equipment (DTE) and Data Circuit-Terminating Equipment (DCE) for terminals operating in the packet mode
34、 and connected to public data networks by dedicated circuit. Presently at the stage of draft. 2 Recommendation V.130 (08/95) - IT-T Recommendation X.30 (1.461) (1993), Support of X.21, X.21 bis and X.20 bis based data terminal equipments DTEs by an Integrated Services Digital Network (ISDN). IT-T Re
35、commendation X.3 1 (1.462) (1993), Support of packet mode terminal equipment by an ISDN. ISO/IEC 21 10:1989, Information technology - Data communication - 25-pole DTWDCE intelface connector and contact number assignments. ISO/IEC 13871, Information technology - Telecommunications and information exc
36、hange between systems - Private telecommunications networks - Digital channel aggregation. - - - 3 Definitions For the purposes of this Recommendation, the following definition applies: 3.1 modec: The term modec is used to refer to a functional block (sometimes called a digital modem) whose overall
37、functionality is equivalent to that of a modem connected to a codec. A modec has no internal analogue components and only digital interfaces. 4 Abbreviations For the purposes of this Recommendation, the following abbreviations are used: BC CLI DTE HLC IPE IWF LLC MIB MSN MTA NT PID SUB TA TE 1 TE2 U
38、DI-TA Bearer Capability Calling Line Identification Data Terminal Equipment High Layer Compatibility In-band Parameter Exchange Interworking Function Low Layer Compatibility Management Information Base Multiple Subscriber Number Multi-protocol Terminal Adaptor Network Termination Protocol Identifica
39、tion Sub-addressing Terminal Adaptor ISDN data terminal DTE with a non-ISDN interface Unrestricted Digital Information with Tones and Announcements 5 Reference models According to clause 3fi.411, the Terminal Adaptor (TA) functional group lies between the R and S reference points and contains functi
40、ons that allow a TE2 (non-ISDN) terminal to use the services provided by an ISDN. Clause 4fi.411 describes various physical configurations involving the TA functional group and the simplest one has interfaces at both the R and S reference points. However, other arrangements are possible and actual i
41、tems of equipment containing the TA functional group may also contain other functional groups, resulting in the interface on the network side not being at the S reference point. Recommendation V.130 (OW95) 3 In general though, for simplicity, the configuration with interfaces at the R and S referenc
42、e points is used throughout this Recommendation. Also, for clarity, the expression “interface at the R (or S) reference point“ is abbreviated to “R (or S) interface“. R - I (2) I I I I I I I I TE I (1 1 (5) (4) - (3) Alternative arrangements on the network side are discussed in the subclause describ
43、ing the network interface functions (5.1.4). S I - I I I I I I I - I I 5.1 Functional reference model The Functional Reference Model in Figure 1 is derived from Figure A.lN.110. Figure 1 shows the main functional blocks that make - t - (I (Note) NT Network termination TE2 Data terminal equipment (DT
44、E) with a non-ISDN interface (1) Terminal interface functions (2) User (U) plane functions (3) Control (C) plane functions (4) Network interface functions (5) Synchronization between User and Control functions (6) Management and maintenance control (i) Local control and management interface NOTE -Th
45、is interface is optional. It is needed if the TA cannot be adequately controlled from the R interface FIGURE 1N.130 Terminal adaptor functional reference model 5.1.1 Terminal interface functions This block provides physical layer functions at the R interface according to applicable Recommendations o
46、r International or National Standards. (These are listed in 8.1.) Alternatively this interface may be internai to a piece of equipment and therefore not subject to standardization. 5.1.2 User (U) plane functions The main U plane function is the adaptation of the users information signalling rate and
47、 format at the R interface to that of the ISDN B- or other channel(s) being used at the S interface. 4 Recommendation V.130 (08/95) ITU-T RECkIN*V*130 95 m 4862593 13608725 183 Additional U plane functions include: - end-to-end mapping of the states of R interface control signals; - in-band notifica
48、tiodcheckinghegotiation of adaptation protocol (for multi-protocol TAS); in-band notificatiorcheckinghegotiation of adaptation protocol parameters; - - handling error conditions detected at the R interface; recovery of timing information (network independent clock); - - end-to-end flow control betwe
49、en TAS (methods are described in both Recommendations V.110 and V.120); - multiplexing of several user connections into one ISDN call; - aggregation of several ISDN calls to provide one user connection. Protocols for this purpose are described in Recommendation H.244 and the complementary International Standard, ISOAEC 13871 ; - detection and optional correction of errors that occur between the TAS; compression of the user information stream to increase the effective throughput; - - encryption of the user information stream for security purposes; - modec function (se
