1、ITU-T RECMN*Q.2030 95 4862.593 05993b3 733 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU GENERAL ASPECTS OF B-ISDN Q.201 O (02/95) BROADBAND INTEGRATED SERVICES SIGNALLING CAPABILITY SET 1 RELEASE 1 DIGITAL NETWORK OVERVIEW - ITU-T Recommendation Q.201 O
2、 (Previously “CCIlT Recommendation”) ITU-T RECMN*Q.ZOLO 35 = 4862531 0.599364 b7T = FOREWORD The 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 a
3、nd issuing Recommen- dations 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 which, in their turn, produce Recommendat
4、ions 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 (Helsinki, March 1-12, 1993). ITU-T Recommendation 4.2010 was prepared by ITU-T Study Group 11 (1993-1996) and was approved under the WTSC Resolution No. 1
5、 procedure on the 7th February 1995. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O ITU 1995 All rights reserved. No part of this publication may be reproduced or utilized i
6、n any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 9 ITU-T RECMN*Q.ZOLO 95 4862593 0599365 50b CONTENTS Page Scope B-ISDN signalling reference configuration . Signalling relations . Abbreviations . Signalling transf
7、er modes . Signalling protocol stacks Basic principles of the Asynchronous Transfer Mode (ATM) . ATM Adaptation Layer (AAL) functions 8.1 . Signalling AAL at the UM . 8.2 Signalling AAL at the “I . Signalling higher layer functions . 9.1 UNI . 9.2 NNI . 1 1 1 3 3 5 6 7 7 7 8 8 8 Recommendation Q.201
8、0 (02/95) i ITU-T RECMN*Q.ZDLO 95 4862591 05993bb 442 SUMMARY This Recommendation provides an introduction to signalling in the broadband integrated services digital network. Included is a presentation of the signalling reference configurations, possible signalling relationships between network enti
9、ties, the signalling protocol stacks used in these configurations and pointers to Recommendations which provide the detailed protocol descriptions. Also included is a brief introduction to the principles of ATM. ii Recommendation Q.2010 (OW95) ITU-T RECHN*Q=ZOLQ 75 = 4862571 0599367 387 Recommendati
10、on Q.2010 BROADBAND INTEGRATED SERVICES DIGITAL NETWORK OVERVIEW - SIGNALLING CAPABILITY SET 1, RELEASE 1 (Geneva, 1995) 1 Scope This Recommendation covers an overview of the basic concepts, reference configurations and protocols related to the provision of signalling capabilities in a Broadband Int
11、egrated Services Digital Network (B-ISDN). 2 B-ISDN signalling reference configuration The overall B-ISDN signalling reference configuration is shown in Figure 1. It includes broadband terminal or terminal adaptation equipment (B-TE1, B-TA), the access distribution function by which terminal equipme
12、nt access the access switching network, the transit switching network and the signalling network. . 6-TE1 B-TA or 6-TE1 or 6-TA TI 162100-94/doi FIGURE VQ.2010 B-ISDN signalling reference confguration 3 Signalling relations Figure 2 depicts the signalling relations in two access distribution configu
13、rations, one in which the terminal equipment accesses the access switching network via Broadband Network Termination Equipment (B-NT2) and one in which the terminal equipment accesses the access switching network directly. Recommendation Q.2010 (02/95) 1 The point-to-point signalling relation Pu is
14、used for call establishment. For point-to-point access at the User-Network Interface (UNI) the point-to-point signalling relation Pu is established permanently and used for call offering, call establishment and call release. The protocol stacks associated with mi are identified in clause 5. B-NTP B-
15、TA To local Exchange B-TA To local Exchange Network NMrk a) Point-to-Point Terminal Equipment with B-NT2 b) Point-topoint Terminai Equipment Tl162110-94/d2 FIGURE UQ.2010 Local distribution (including terminal equipment) Figures 3 and 4 show the signalling relations in the access switching and trans
16、it switching networks, respectively. :J?TL the SSP is specific to the needs of the service application. The following understanding about the CP and SSP exists at the UNI and “I respectively. 1 4 T1162150-94d06 FIGURE 9/Q.2010 Functional division of the signalling AAL 8.1 Signalling AAL at the UNI T
17、he protocol stacks showing the AAL functionality at the UNI for point-to-point are illustrated in Figure 6. 8.2 Signalling AAL at the NNI The protocol stack showing the AAL functionality at the “I for point-to-point application in the associated mode and quasi-associated mode is illustrated in Figur
18、es 7 and 8. Recommendation Q.2010 (02/95) 7 ITU-T RECMN*Q.2010 95 W 4862591 0599374 519 9 Signalling higher layer functions A stage 2 service description is provided in Recommendation Q.71. The higher layer protocols for signalling are, in general, responsible for call and bearer control. As these f
19、unctions differ somewhat at UNI and at the NNI, different protocols are used. 9.1 UNI The callkonnection control functions are: - call establishment and release? - - compatibility checking; - - bearer establishment and release, for point-to-point VCCs2) ; support of N-ISDN services and signalling in
20、terworking between N-ISDN and B-ISDN; support of some supplementary services (see Recommendations Q.295 1 and Q.2957). 9.2 NNI The callhearer connection control functions are: - call establishment and releasel); - - - - interworking with N-ISDN services. Signalling network functions are according to
21、 Recommendation Q.704. For SCS-1 (Release l), the signalling protocols are based on the Signalling System No. 7 Recommendation. bearer connection establishment and release, for point-to-point VCCs2); transfer of access transport information; support of some supplementary services (see Recommendation
22、 Q.2730); i) For SCS-1 (Release l), calls and bearer connections are established and released simultaneously. 2, Other communication configurations will be studied during the 1993-1996 study period. For SCS-1 (Release i), the signalling protocols are based on the DSS 1 and ISUP Recommendations. 8 Recommendation Q.2010 (02/95)
