1、National Standard of Canada CAN/CSA-ISO/IEC 13871 -97 International Standard ISO/IEC 13871: 1995 (first edition, 1995-12-15) has been adopted without modification as CSA Standard CAN/CSA-ISO/IEC 13871-97, which has been approved as a National Standard of Canada by the Standards Council of Canada. IS
2、SN 031 7-5669 February 1997 Information technology - Telecommunications and information exchange between systems - Private telecommunications networks - Digital channel aggregation Technologies de /information - Telecommunications et echange dtnformation entre systemes - Reseaux privds de telecommun
3、ications - Agregation de canal numerique Reference number ISOilEC 13871 :I 995lEl LAssociation canadienne de normalisation (CSA), sous les auspices de laquelle cette Norme nationale a 8th prkparbe, a rep ses lettres patentes en 191 9 et son accreditation au sein du Systeme de normes nationales par l
4、e Conseil canadien des normes en 1973. Association daffiliation libre, sans but lucratif ni pouvoir de rkglernentation, elle se consacre A IBlaboration de normes et a ia certification. Les norrnes CSA reflhtent le consensus de producteurs et dusagers de partout au pays, au nombre desquels se trouven
5、t des fabricants, des consommateurs, des detaillants et des reprksentants de syndicats, de corps professionnels et dagences gouvernementales. Lutilisation des normes CSA est trbs repandue dans lindustrie et le commerce, et leur adoption h divers ordres de Ikgislation, tant municipal et provincial qu
6、e fkderal, est chose courante, particulikrement dans les domaines de la sant6, de la s6curit8, du bhtiment, de la construction et de Ienvironnement. Les Canadiens dun bout A Iautre du pays tkmoignent de leur appui au travail de normalisation men6 par la CSA en participant benkvolement aux travaux de
7、s comites de la CSA et en appuyant ses objectifs par leurs cotisations de membres de soutien. Les quelque 7000 volontaires faisant partie des comites et les 2000 mernbres de soutien constituent Iensemble des membres de la CSA parmi lesquels ses administrateurs sont choisis. Les cotisations des membr
8、es de soutien representent me source importante de revenu pour les services de soutien A la normalisation volontaire. LAssociation offre des services de certification et de mise A Iessai qui appuient et complbtent ses activites dans le domaine de 18laboration de normes. De manikre I assurer Iintkgri
9、te de son processus de certification, IAssociation procede de faqon rhgulikre et continue A Iexamen et h Iinspection des produits portant la marque CSA. Outre son siege social et ses laboratoires a Etobicoke, la CSA possede des bureaux rkgionaux dans des centres vitaux partout au Canada, de m6me que
10、 des agences dinspection et dessal dans huit pays. Depuis 1919, IAssociation a parfait les connaissances techniques qui Iui permettent de remplir sa mission dentreprise, savoir la CSA est un organisme de services independant dont la mission est doffrir une tribune libre et efficace pour la rkalisati
11、on dactivitks facilitant lkchange de biens et de services par lintermkdiaire de services de normalisation de certification et autres, pour repondre aux besoins de nos clients, tant A 16chelle nationale quinternationale. The Canadian Standards Association (CSA), under whose auspices this National Sta
12、ndard has been produced, was chartered in 191 9 and accredited by the Standards Council of Canada to the National Standards system in 1973. It is a not-for-profit, nonstatutory, voluntary membership association engaged in standards development and certification activities. CSA standards reflect a na
13、tional consensus of producers and users - including manufacturers, consumers, retailers, unions and professional organizations, and governmental agencies. The standards are used widely by industry and commerce and often adopted by municipal, provincial, and federal governments in their regulations,
14、particularly in the fields of health, safety, building and construction, and the environment, Individuals, companies, and associations across Canada indicate their support for CSAs standards development by volunteering their time and skills to CSA Committee work and supporting the Associations objec
15、tives through sustaining memberships. The more than 7000 committee volunteers and the 2000 sustaining memberships together form CSAs total membership from which its Directors are chosen. Sustaining memberships represent a major source of income for CSAs slandards development activities. The Associat
16、ion offers certification and testing services in support of and as an extension to its standards development activities. To ensure the integrity of its certification process, the Association regularly and continually audits and inspects products that bear the CSA Mark. In addition to its head office
17、 and laboratory complex in Etobicoke, CSA has regional branch offices in major centres across Canada and inspection and testing agencies in eight countries. Since 1919, the Association has developed the necessary expertise to meet its corporate mission: CSA is an independent service organization who
18、se mission is !a provide an open and effective forum for activities facilitating the exchange of goods and services through the use of standards, certification and related services to meet national and international needs. Pour plus amples renseignernents sur les services de la CSA, sadresser a For
19、further information on CSA services, write to 178, boulevard Rexdale 178 Rexdale Boulevard Etobicoke, Ontario, M9W 1R3 Canada Association canadienne de normalisation Canadian Standards Association Le Conseil canadien des normes est Iorganisme de coordination du Systbme de normes nationales, une fede
20、ration dorganismes indkpendants et autonomes qui travaillent au dkveloppement et A Iamklioration de la normalisation volontaire dans IintkrSit national. Les principaux buts du Conseil sont dencourager et de promouvoir a normalisation volontaire comme moyen damkliorer Idconomie nationale, damdiorer l
21、a sante, la s6curite et le bien-6tre du public, daider et de proteger le consommateur, de faciliter le commerce national et international et de favoriser a cooperation internationale dans le domaine de la normalisation. nombre de personnes comphtentes dont les intkrMs rkunis forrnent, au degre le pl
22、us cet aspect demeure la responsabilitk de Iorganisme rkdacteur de normes accrkdite. pkriodiques ; cest pourquoi il est recommand6 aux utilisateurs de se procurer 18dition la PLUS rkcente de la norme auprhs de Iorganisme qui Ia prbparbe. Une Norrne nationale du Canada est une norme, approuvke par le
23、 Conseil canadien des normes, qui reflbte une entente raisonnable parmi les points de vue dun certain Lapprobation dune norme en tant que Norme nationale du Canada indique quelle est conforme aux mkthodes et critkres 6tablis par le Conseil canadien des normes. II est recommand4 aux personnes qui ont
24、 besoin de normes de se servir des Norrnes nationales du Canada lorsque ia chose est possible. Ces norrnes font lobjet dexamens The Standards Council of Canada is the coordinating body of the National Standards system, a federation of independent, autonomous organizations working towards the further
25、 development and improvement of voluntary standardization in the national interest. The principal objects of the Council are to foster and promote voiuntary standardization as a means of advancing the national economy, benefiting the health, safety, and welfare of the public, assisting and protectin
26、g the consumer, facilitating domestic and international trade, and furthering international cooperation in the field of standards. A National Standard of Canada is a standard which has been approved by the Standards Council of Canada and one which reflects a reasonable agreement among the views of a
27、 number of capable individuals whose collective interests provide to the greatest practicable extent a balance of representation of producers, users, consumers, and others with relevant interests, as may be appropriate to the subject in hand. It normally is a standard which is capable of making a si
28、gnificant and timely contribution to the national interest. Approval of a standard as a National Standard of Canada indicates that a standard conforms to the criteria and procedures established by the Standards Council of Canada. Approval does not refer to the technical content of the standard; this
29、 remains the continuing responsibility of the accredited standards-development organization. Those who have a need to apply standards are encouraged to use National Standards of Canada whenever practicable. These standards are subject to periodic review; therefore, users are cautioned to obtain the
30、latest edition from the organization preparing the standard. La responsabilitk dapprauver les Normes nationales du Canada incornbe au The responsibility for approving National Standards of Canada rests with the Canseil canadien des normes Standards Council of Canada 45, rue OConnor, Bureau 1200 45 O
31、Connor Street, Suite 1200 Ottawa, Ontario, K1 P 6N7 Canada Eien que le but premier vise par cette norme soit enonce sous sa rubrique Dornaine dapplication, il est important de retenir quii incornbe a Iutilisateur de juger si la norme convient a ses besoins pariicuiiers. Although the intended primary
32、 application of this Standard is stated in its Scope, it is important to note that it remains the responsibility of the user to judge its suitability for fheir particular purpose. Information technology - Telecommunications and information exchange between systems - Private telecommunications networ
33、ks - Digita! channel aggregation CAN/CSA-ISO/EC 7 3871 -97 CAN/CSA-ISO/IEC 13871-97 Information technology - Telecommunications and information exchange between systems - Private telecommunications networks - Digital channel agpegafion CSA Preface Standards development within the tnformation Technol
34、ogy sector is harmonized with international standards development. Through the CSA Technical Committee on Information Technology (TCIT), Canadians serve as the Canadian Advisory Committee (CAC) on ISO/IEC joint Technical Committee 1 on Information Technology (ISO/IEC JTC1) for the Standards Council
35、of Canada (SCC), the IS0 member body for Canada and sponsor of the Canadian National Committee of the IEC. Also, as a member of the International Telecommunication Union (ITU), Canada participates in the International Telegraph and Telephone Consultative Committee (ITU-T). This International Standar
36、d was reviewed by the CSA TClT under the jurisdiction of the Strategic Steering Committee on Information Technology and deemed acceptable for use in Canada. (A committee membership list is available on request from the CSA Committee Administrator.) From time to time, ISO/IEC may publish addenda, cor
37、rigenda, etc. The CSA TClT will review these documents for approval and publication. For a listing, refer to CSA Information Products Catalogue or CSA Info Update or contact a CSA Sales representative. This Standard has been formally approved, without modification, by these Committees and has been a
38、pproved as a National Standard of Canada by the Standards Council of Canada. February 1997 0 Canadian Standards Association - 1997. All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior permission of the publ
39、isher. /SO/iEC material is reprinted with the permission of the publisher. February 7997 CSA/I I N T E R N AT IO N A L STANDARD ISO/IEC 1387 I First edition 1995-1 2-1 5 Information technology - Teleco m m u n icat i o ns and i nf o r m at i o n exchange between systems - Private telecommunications
40、networks - Digital channel aggregation Technologies de linformation - Telecommunications et echange dinformation entre syst if the incoming signal is H.221 framed but neither (SM- comp nor (6B-HO-comp is included in the capability set, then the remote end-point is a self-aggregating type of H.320 te
41、rminal and ISOlIEC 13871 aggregation is not possible. Set Flag 1 = 0 I Set Flag 1 = 1 L Answering endpoint aggregancn lo distingJish Callrnq/Answenng endpoints , framing I Condition 2 - .ock for frcm SCE SM-co lpj I 1 Condition 3 7 for H.244 aggregation Forward framed PCM from SC stde to MC SI H 221
42、 fam ng detected (Note 1) dereci B d Smtch transmitted s gral to IS0 13.971 ! 1 Note 1 Answenng endfmnt inibal y transmits all ores Yetiher H 244 nor ISC 13871 signals detecied with n 10s Figure 2 - Selection of ISOnEC 13871 or ITU-T H.244 aggregation 4 0 ISOAEC ISODEC 13871: 1995(E) 6 Basic Princip
43、les This International Standard describes a means for providing a high speed serial data stream by use of multiple, independent 56/64 kbits channels. These channels are individually connected over the switched digital network (public, prjsate, etc.). At the transmitting end: user data is placed in a
44、 framing structure in each bearer channel and transmitted over multiple, independent channels. At the receiving end, all channels are phase aligned and synchronized (using the framing structure) to recreate the original data stream. This framing and synchronization is transparent to the attached app
45、lication. Due to the network routing the channels used for the wideband connection independently of each other, the data in each channel might be individually delayed relative to the data in other channels. The frame structure described herein for each 56/64 kbitls bearer channel provides for the al
46、ignment of data octets from the individual channels to their original sequence before reforming the individual channels into a composite serial data stream at the terminating end. Overall transit delay for the end-to-end connection is equal to the longest transit delay from all the channels plus a c
47、onstant delay due to the frame alignment that depends on implementation. Once aligned, data transfer may be constantly monitored throughout the call. The failure of a channel, for reasons such as call disconnection, phase slip or high enor rate, may be automatically detected. Various fault isolation
48、 and recovery procedures are defined in response to these scenarios. Individual switched 56/64 calls can be combined to form a single transparent N x 56/64 channel. NOTES 1 This algorithm will maintain bit and octet sequence integrity in that it will deliver user bits and octets to the remote endpoi
49、nt in the same order and timing relationships as were received on the originating endpoint (except in cases of lost frame alignment). For applications that require octet timing to be maintained across the network (i.e., an octet of user data clocked into the transmitting endpoint must be clocked out as an octet of user data at the receiving endpoint), it is recommended that the first octet of user data transmitted across rhe network (i.e., the first octet transmitted after delay equalization is achieved) be placed in the
