1、STDmITU-T RECMN I-4b4-ENGL 1999 = 4Bb2591 0657346 026 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU 1.464 (02199) SERIES I: INTEGRATED SERVICES DIGITAL NETWORK ISDN user-network interfaces - Multiplexing, rate adaption and suppori of existing interfaces
2、Multiplexing, rate adaption and support of existing interfaces for restricted 64 kbit/s transfer capa bi I ity ITU-T Recommendation I .464 (Previously CCITT Recommendation) STDmITU-T RECMN 1-4b4-ENGL 1999 4862593 Ob57347 Tb2 ITU-T 1-SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERAL
3、STRUCTURE Terminology Description of ISDNs General modelling methods Telecommunication network and service attributes General description of asynchronous transfer mode Scope General aspects of services in ISDN Common aspects of services in the ISDN Bearer services supported by an ISDN Teleservices s
4、upported by an ISDN Supplementary services in ISDN Network functional principles Reference models Numbering, addressing and routing Connection types Performance objectives Protocol layer requirements General network requirements and functions Application of I-series Recommendations to ISDN user-netw
5、ork interfaces Layer I Recommendations Layer 2 Recommendations Layer 3 Recommendations SERVICE CAPABILITIES OVERALL NETWORK ASPECTS AND FUNCTIONS ISDN USER-NETWORK INTERFACES 1.110-1.119 I. 120-1.129 I. 130-1.139 I. 140-1.149 I. 150-1.199 I .2 00-1.209 1.210-1.219 I .220-1.229 1.230-1.239 I .240-1.2
6、49 I .250-1.299 1.310-1.319 1.320-1.329 1.330-1.339 1.340-1.349 1.350-1.359 1.360-1.369 1.370-1.399 I.420-I .429 1.430-1.439 1.440-1.449 1.450-1.459 Multiplexing, rate adaption and support of existing interfaces 1.460-1.469 Aspects of ISDN affecting terminal requirements I .47O-l.499 INTERNETWORK IN
7、TERFACES I .500-l. 599 MAINTENANCE PRINCIPLES I .600-1.699 B-ISDN EQUIPMENT ASPECTS ATM equipment I .730-I. 739 Transport functions I .740-1.749 Management of ATM equipment 1.750-1.799 For further details, please refer to ITU-T List of Recommendations. STD-ITU-T RECMN 1-4bq-ENGL la999 m 48b25L Ob573
8、48 T9 H ITU-T RECOMMENDATION 1.464 MULTIPLEXING, RATE ADAPTION AND SUPPORT OF EXISTING INTERFACES FOR RESTRICTED 64 kbit/s TRANSFER CAPABILITY Source ITU-T Recommendation 1.464 was revised by ITU-T Study Group 13 (1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the 15” Febru
9、ary 1999. Recommendation 1.464 (02/99) 1 STDmITU-T RECMN 1-464-ENGL 1999 M 48b259L 0657349 835 m FOREWORD ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent o
10、rgan of the ITU. The 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. establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommen
11、dations 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 collaborative basis with IS0 and IE
12、C. I The World Telecommunication Standardization Conference (WTSC), which meets every four years, NOTE In this Recommendation the term recognized operating agency (ROA) includes any individual, company, corporation or governmental organization that operates a public correspondence service. The terms
13、 Administration, ROA and public courespondence are defined in the Constitution of the ITU (Geneva, 1992). . INTELLECTUAL PROPERTY RIGHTS The ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right.
14、 The 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 approval of this Recommendation, the ITU had not received notice of in
15、tellectual 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 database. O ITU 1999 All rights reserved. No part of th
16、is 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. II Recommendation 1.464 (02/99) - STD-ITU-T RECMN 1-464-ENGL 1999 m 48b2591 Ob57350 557 m CONTENTS Page Appendix - HDL
17、C inverted mode for restricted transport capabilities . . . . . . . . . . . . . . . . . . . 2 . Recommendation 1.464 (02/99) 111 STD-ITU-T RECMN 1-4bY-ENGL 1999 W 4862591 Ob57351 493 m Recommendation 1.464 MULTIPLEXING, RATE ADAPTION AND SUPPORT OF EXISTING INTERFACES FOR RESTRICTED 64 kbit/s TRANSF
18、ER CAPABILITY (Malaga-Torremolinos I984: amended at Melbourne, I988; revised in I991 and I999) Restricted 64 kbWs transfer capability is defined as “64 kbits octet-structured capability with the restriction that an all-zero octet is not permitted“. The procedures given in Recommendations 1.460, I.46
19、1K.30, 1.462K.3 1, 1.463N.110 and 1.465/V. 120 for rate adaption, multiplexing and support of existing interfaces for 64 kbit/s, are fully compatible with the restricted 64 kbit/s transfer capability except for the following limitations: i) For time division multiplexing, the eighth bit of each octe
20、t of the 64 kbits stream will be set to binary 1. This procedure is the same as that used for time division multiplexing into an unrestricted 64 kbit/s channel where the full 64 kbits is not utilized. For adapting X.25 DTEs as described in Recommendation 1.462K.31 where rate adaption (see 7.3.2K.31)
21、 is accomplished by “flag stuffing“ or adapting DTEs for circuit mode as described in Recommendation 1.465N.120, for use with restricted 64 kbits transfer capabilities, the data is first rate adapted to a 56 kbit/s rate and the resulting bit stream is placed into a 64 kbit/s channel using the first
22、seven bits of each byte with the eighth bit of each byte set to a binary 1. An alternative approach, which uses the full 64 kbit/s capacity of the transport capability and which may be used by mutual agreement, is described in Appendix I. When adapting V-series DTEs which operate at DTE rates of 24
23、kbits, 28.8 kbit/s, 38.4 kbit/s or 56 kbits (using the alternative frame structure in Table 7N.11 O), using the method described in Recommendation I.463N.110, an all-zero octet can appear in the 64 kbits stream. This makes DTEs operating at such rates unsuitable for use with bearers having restricte
24、d 64 kbits transfer capabilities. ii) iii) The procedures in Recommendation 1.462X.3 1 apply only to synchronous terminals. The procedures in Recommendations 1.460, 1.461/X.30 and 1.463N. 1 1 O apply to both synchronous and asynchronous terminals. The procedures in Recommendation 1.465V. 120 apply t
25、o synchronous HDLC based, synchronous bit transparent, and asynchronous terminals. Recommendation 1.464 (02199) 1 STD-ITU-T RECMN I-4b4-ENGL 1999 a 4862591 Ob57352 32T m APPENDIX I HDLC inverted mode for restricted transport capabilities Inverted HDLC is adequate for the transmission of data sequenc
26、es using HDLC-based protocols (i.e. Recommendations X.25 and V.120) over B-channel connections independent of whether such connection is restricted or unrestricted. In the inverted mode, a binary 1 is sent as a pulse and a binary O is sent as the absence of a pulse. An “abort“ must be restricted to
27、a sequence of seven consecutive binary 1 s and on all binary 1 s idle must be sent as repeated transmission of a sequence of seven consecutive binary 1 s followed by a binary O. The all 1 s idle appears as a string of continuous aborts. A receiver, which must distinguish the all binary Is idle, shal
28、l interpret two or more consecutive aborts as idle. Where continuous aborts cause difficulties, the receiver must include the capability of converting continuous aborts to an all binary 1 s idle. For basic access, when the used B-channel is not connected, the TE must send all 1s. When the B-channel
29、is connected, the TE shall initiate the transmission of interframe time fill (flags) immediately. 2 Recommendation 1.464 (02/99) , _. STD-ITU-T RECMN 1.4b4-ENGL 1999 111 48b259L Ob57354 IT2 E Series A Series B Series C Series D Series E Series F Series G Series H Series I Series J Series K Series L
30、Series M Series N Series O Series P Series Q Series R Series S Series T Series U Series V Series X Series Y Series Z ITU-T RECOMMENDATIONS SERIES Organization of the work of the ITU-T Means of expression: definitions, symbols, classification General telecommunication statistics General tariff princi
31、ples Overall network operation, telephone service, service operation and human factors Non-telephone telecommunication services Transmission systems and media, digital systems and networks Audiovisual and multimedia systems Integrated services digital network Transmission of television, sound progra
32、mme and other multimedia signals Protection against interference Construction, installation and protection of cables and other elements of outside plant TIvN and network maintenance: international transmission systems, telephone circuits, telegraphy, facsimile and leased circuits Maintenance: intern
33、ational sound programme and television transmission circuits Specifications of measuring equipment Telephone transmission quality, telephone installations, local line networks Switching and signalling Telegraph transmission Telegraph services terminal equipment Terminals for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communications Global information infrastructure Programming languages Printed in Switzerland Geneva, 1999
