1、 STD-ITU-T RECMN F-811-ENGL L77b Li8b257L b23777 858 m INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU SERIES F: NON-TELEPHONE TELECOMMUN SERVI CES ISDN services F.81 I CAT (O 7/9 6) ON Broadband connection-oriented bearer service ITU-T Recommendation F.81
2、 I (Previously “CCITT Recommendation“) ITU-T F-SERIES RECOMMENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES TELEGRAPH SERVICE Operating methods for the international public telegram service The gentex network Message switching The international telernessage service The intemational telex service
3、Statistics and publications on intemational telegraph services Scheduled and leased communication services Phototelegraph service Mobile services and rnultidestination satellite services MOBILE SERVICE TELEMATIC SERVICES Public facsimile service Teletex service Videotex service General provisions fo
4、r telernatic services MESSAGE HANDLING SERVICES DIRECTORY SERVICES DOCUMENT COMMUNICATION Document communication Programming communication interfaces DATA TRANSMISSION SERVICES F. l-F. 109 F. 1 -F. 19 F.20-F.29 F.30-F.39 F.40-F.5 8 F.59-F.89 F.90-F.99 F. 100-F. 104 F.105-F.109 F.110-F.159 F.110-F. 1
5、59 F. 160-F.399 F. 160-F. 199 F.200-F.299 F.3 00-F.349 F.350-F.399 F .400-F .499 F.500-F.549 F.550-F.599 F.550-F.579 F.580-F.599 F.600-F.699 II AUDIOVISUAL SERVICES F.700-F.799 UNIVERSAL PERSONAL TELECOMMUNICATION HUMAN FACTORS F .850-F.899 F.900-F.999 For further details, please refer to ITU-T List
6、 of Recommendations. 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 and issuing Recommen- dations on them with a view to standardizi
7、ng 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 tum, produce Recommendations on these topics. The approval of Recommendations by the Mem
8、bers of the ITU-T is covered by the procedure laid down in WTSC ResolutionNo. 1 (Helsinki, March 1-12, 1993). ITU-T Recommendation F.811 was revised by ITU-T Study Group 1 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 19th of July 1996. NOTE In this Recommendation, th
9、e expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O ITU 1997 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including phot
10、ocopying and microfilm, without permission in writing from the ITU. Recommendation F.811 (07196) 1 CONTENTS Definition . Description . 2.1 General description . 2.2 Specific terminology . Procedures 3.1 On demand mode 3.2 Reserved mode 3.3 Permanent mode . Network capabilities for charging Interwork
11、ing requirements . Interaction with supplementary services Annex A . Broadband connection-oriented bearer service . Annex B . Alphabetical list of abbreviations used in this Recommendation Annex C - Narrow-band emulated services 64 kbits bearer communication usable for speech . 64 kbits bearer commu
12、nication usable for 3.1 kHz audio . 64 kbits unrestricted bearer service . Annex D - References . C.l C.2 C.3 11 Recommendation F.811 (07/96) Page 1 1 1 2 4 4 5 11 14 14 14 15 16 16 16 17 17 18 SUMMARY The Broadband Connection-Oriented Bearer Service (BCOBS) provides unrestricted transfer of digital
13、 information between TB reference points, or SB reference points when TB and SB reference points are coincident. This bearer service flexibly supports connection-oriented communications at any bit rate over a virtual channel connection. This bit rate can be approximately constant to support constant
14、 bit rate traffic or it can be highly variable to support variable bit-rate traffic. .*. Recommendation F.811 (07196) 111 STD-ITU-T RECMN F-BLL-ENGL 199b R 48b2.591 0b23802 T45 Recommendation F.811 BROADBAND CONNECTION-ORIENTED BEARER SERVICE (revised in 1996) 1 Definition The Broadband Connection-O
15、riented Bearer Service (BCOBS) provides unrestricted transfer of digital information between TB reference points, or SB reference points when TB and SB reference points are coincident. This bearer service flexibly supports connection-oriented communications at any bit rate over a virtual channel con
16、nection. This bit rate can be approximately constant to support Constant Bit Rate (CBR) traffic or it can be highly variable to support Variable Bit Rate (VBR) traffic. Signalling information transfer will be provided over a separate signalling virtual channel. 2 Description 2.1 General description
17、The service provides cell based communications in a bidirectional symmetric, bidirectional asymmetric or unidirectional fashion using virtual channel connections in the Broadband Integrated Services Digital Network (B-ISDN). For each communication of this service, the user and the SP agree on the us
18、e of one of the ATM Transfer Capabilities (ATCs) defined in Recommendation I.371 11. This service is provided in Permanent, Reserved and on-Demand mode. In permanent mode the user subscribes to one or more permanent communications, specifying all the parameters to characterize them. In reserved mode
19、 the user gets at subscription the capability to request, to modi and to release reserved communications for the Subscription duration. After the subscription, at any time the user can request by management procedures to reserve a communication specieing all the parameters to characterize it. In (sw
20、itched) on-demand mode the user gets at subscription the capability to request, to modi and to release a (switched) on-demand call for the subscription duration. After the subscription, at any time the user can request to set up a call specifying all the parameters to characterize it. This Recommend
21、ation focuses on the provisioning of the service in a point-to-point communication configuration for the (switched) on-demand mode and in a point-to-point and unidirectional point-to-multipoint configurations for permanent and reserved modes; other communication configurations are for further study.
22、 The operations (from the users point of view) necessary for the activation of a communication (fi-om the network point of view) are successively (or simultaneously) as identified in Table 1. For these complete operations, there are three possibilities: 1) per management procedures; 2) per signallin
23、g procedures; 3) per fast allocation procedures. Table 2 summarises the different options. This Recommendation specifies only procedures for the simultaneous request of establishment and activation (i.e. according to the third column). It is compatible with the separation of the request of establish
24、ment and activation (i.e. column two and three of Table 2) but procedures are for further study. Recommendation F.811 (07196) 1 - STD.ITU-T RECMN F.811-ENGL 177b 48b2571 b23803 781 Request of a route including the ATC in order to be connected to (an)other user(s) /I TABLE 1E.811 User request and res
25、ulting actions in the network Marking the route: it corresponds to the establishment of the associated ATM connection(s) without the resources supporting the communication 1 User request 2 -1 I Resulting actions in the network Negotiation of the resources, i.e. request of traffic Allocation of the r
26、esources: it corresponds to the activation parameter(s), QOS classes and OAM flows per ATM connection supporting the communication ofthecommunication reserved (switched) on-demand M M M compatible S compatible RM S S S compatible M compatible RM TABLE 2E.811 Establishment and activation requests Neg
27、otiation Modes permanent Connection establishment request (without resources): i.e. request of the route including the ATC only not applicable Connection activation request, i.e. negotiation of traffic parameter(s), QOS classes and OAM flows per ATM connection only not applicable Simultaneous reques
28、t of establish- ment and activation, Le. simulta- neous request of the route and negotiation of the traffic parame- ter(s), QOS ciasses and OAM flows per ATM connection at subscription 2.2 Specific terminology For the purposes of this Recommendation, the following definitions apply. 2.2.1 ATM transf
29、er capability: See Recommendation I.3711. ATM Transfer capabilities are DBR, SBR, ABR, ABT-DT and ABT-IT. The specification of the relevant switching protocol at UNI to negotiate the ATM Transfer capability is contained in Recommendations Q.293 1 9 and 4.2961 1 i. The management protocols at UNI to
30、negotiate the ATM Transfer capability are for further study. 2.2.2 cell delay variation: See Recommendation 1.3562. 2 Recommendation F.811 (0796) 2.2.3 2.2.4 2.2.5 2.2.6 2.2.7 2.2.8 cell delay variation tolerance: See Recommendation 1.371 i. cell loss ratio: See Recommendation 1.3562. cell transfer
31、delay: See Recommendation 1.3562. initiating manager: The manager issuing a request to the Service Management Entity (SME). intrinsic burst tolerance: See Recommendation 1.371 i. ISDN number: A number conforming to the numbering plan and structure specified in Recommenda- tion E.1644. 2.2.9 involved
32、 manager: The manager receiving a request issued by another initiating manager. 2.2.10 manager: In reserved mode, it is the functional entity authorized to send through x reference point (as defined in Recommendation M.30103) the communication registration requests, the communication modification re
33、quests and interrogation requests, on behalf of the users to which it is related at the subscription time. 2.2.11 integer number of cell per second. maximum cell rate: See Recommendation I.3711. The Maximum Cell Rate is declared by the user as an 2.2.12 integer number of cell per second. minimum cel
34、l rate: See Recommendation 1.3711. The Minimum Cell Rate is declared by the user as an 2.2.13 number of cell per second. peak cell rate: See Recommendation 1.3711. The Peak Cell Rate is declared by the user as an integer 2.2.14 as an integer number of cell per second. peak re-negotiation rate: See R
35、ecommendation I.3711. The peak re-negotiation rate is declared by the user 2.2.15 QOS class repeats within each period for the communication duration. periodic communication: A communication whose same scheme of values of source traffic descriptor and 2.2.16 end Cell Loss Ratio, end-to-end Cell Tran
36、sfer Delay, end-to-end Cell Delay Variation. quality of service class: A set of values associated to the following ATM performance parameters: end-to- 2.2.17 service type: See Recommendation I.3711. 2.2.18 communication registration requests, communication modifications requests and interrogation re
37、quests are addressed. service management entity (SME): In reserved mode the SME is the functional entity to which managers 2.2.19 source traffic descriptor: The set of traffic parameters associated to an ATM transfer capability. For DBR it is given by the Peak Cell Rate and the associated Cell Delay
38、 Variation Tolerance. For SBR it is given by the Peak Cell Rate and the associated Cell Delay Variation Tolerance, the Sustainable Cell Rate, the Intrinsic Burst Tolerance and the associated Cell Delay Variation Tolerance. For ABR it is given by the Peak Cell Rate and the Minimum Cell Rate. For ABT-
39、DT and ABT-IT it is given by the Maximum Cell Rate and the associated Cell Delay Variation Tolerance, the Peak re-negotiation rate and the associated Cell Delay Variation Tolerance, the Sustainable Cell Rate, the Intrinsic Burst Tolerance and the associated Cell Delay Variation Tolerance. See Recomm
40、endation 1.371 i. 2.2.20 integer number of cell per second. sustainable cell rate: See Recommendation 1.371 i. The Sustainable Cell Rate is declared by the user as an 2.2.21 traffic contract: See Recommendation 1.37 1 i. 2.2.22 reference point. It communicates with the manager for the purpose of bei
41、ng controlled and/or monitored. user: Each of the subscribers functional entity that sends or receives ATM cells through TB orTB/SB Recommendation F.811 (07196) 3 STD-ITU-T RECMN F-BLL-EFJGL L99b P 4L2591 Ob238U5 754 m 3 Procedures 3.1 On demand mode 3.1.1 Provision/withdrawal By arrangement with th
42、e SP. The beginning time of provision corresponds to the time of service subscription; the time of withdrawal to the end time of subscription. 3.1.2 Normal procedures 3.1.2.1 Activation/deactivation/registration By arrangement with SP. 3.1.2.2 Invocation and operation User-network signalling is done
43、 over a separate signalling channel. 3.1.2.2.1 Procedures at call set-up are specific for every configuration. However, the following definitions and principles apply to all the configurations. The source traffic descriptor consists of a pair of values for every parameter to define the communication
44、 in both directions. Call Set-up originating the service The QOS class defines the QOS required by the user for the communication. If the value is not specified, a default value is assumed. A pair of values is required to define the communication in both directions. The call is originated by the use
45、r requesting from the network the required bearer service (call Set-up request). The call request includes the following parameters: Communication configuration - ISDN number of the called user. ATM traffic contract on communication basis - ATM transfer capability (according to 5.5.1.1/i.3711, the A
46、TCjs the same in both directions if the communication is bidirectional); source traffic descriptor in each direction (see Recommendation 1.371 i); QOS class in each direction; Peak Cell Rate of the OAM F5 user cell flow and associated Cell Delay Variation Tolerance (for DBR, ABT-IT, ABT-DT only) in
47、each direction (the support of the separation of the user OAM F5 flow and the user data flow is an SP option). - - - AAL parameters - AAL parameters: required by the network only for interworking purpose (e.g. with N-ISDN). Within B-ISDN the user may specifi them for end-to-end matter: the AAL is tr
48、ansparent to the network. Service facilities - Service type (optional, i.e. it is a user option to use this parameter). For the time being, the identified service types are the emulated narrowband bearer services (see Annex C). If the service type is provided, the consistency between the service typ
49、e and the other parameters shall be checked within the network (see Annex C); if there is a lack of consistency, the value of the parameters considered within the network are the implicit values as provided in Annex C; afterwards, any notification to the calling user and any indication to the called user(s) will include the implicit values (considered within the network). 4 Recommendation F.811 (07/96) After initiating a call, the calling user will receive an acknowledgement that the network is able to process the call. An
