1、 STD*ITU-T KECMFJ 1-233-1 ANNEX F-ENGL 1996 R qBb2591 Ob31740 T71 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU 1.2334 Annex F (07196) SERIES I: INTEGRATED SERVICES DIGITAL NETWORK Service capabilities - Bearer services supported by an ISDN Frame mode be
2、arer services: ISDN frame relaying bearer service Annex F: Frame relay multicast ITU-T Recommendation 1.233-1 - Annex F (Previously CCITT Recommendation) ITU-T I-SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERAL STRUCTURE 1.1 00-1.199 Terminology 1.110-1.119 Description of ISDNs I.
3、120-1.129 General modelling methods I. 130-1.1 39 Telecommunication network and service attributes I. 140-1.149 General description of asynchronous transfer mode I. 1 50-1.1 99 SERVICE CAPABILITIES 1.200-1.299 Scope 1.200-1.209 General aspects of services in ISDN I .2 1 0-1.2 1 9 Common aspects of s
4、ervices in the ISDN I .220-I. 229 II Teleservices supported 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 Applic
5、ation of I-series Recommendations to ISDN user-network interfaces Layer 1 Recommendations Layer 2 Recommendations Layer 3 Recommendations Multiplexing, rate adaption and support of existing interfaces Aspects of ISDN affecting terminal requirements OVERALL NETWORK ASPECTS AND FUNCTIONS ISDN USER-NET
6、WORK INTERFACES INTERNETWORK INTERFACES MAINTENANCE PRINCIPLES B-ISDN EQUIPMENT ASPECTS ATM equipment Management of ATM equipment 1.240-1.249 1.250-1.299 1.300-1.399 1.310-1.319 I .320-1.329 1.330-1.339 1.340-1.349 1.350-1.359 1.360-1.369 1.370-1.399 1.400-1.499 1.420-1.429 1.430-1.439 I .440-1.449
7、1.450-1.459 I .460-1.469 1.470-1.499 I .500-1.599 1.600-1.699 1.700-I .799 1.730-1.749 I .750-1.799 For further details, please refer to ITU-T List of Recommendations. STD-IU-T RECMN I.233-1 AFINE:( F-ENGL L77b B idb259L Ob31742 Ab-q D ITU-T RECOMMENDATION 1.233.1 FRAME MODE BEARER SERVICES: ISDN FR
8、AME RELAYING BEARER SERVICE Annex F Frame relay multicast Source ITU-T Recommendation 1.233.1, Annex F was revised by ITU-T Study Group 1 (1993-1996) and was approved under the WTSC Resolution Nol procedure on the 19th of July 1996. STD-ITU-T RECMN 1-233-4, ANNEX F-ENGL 1776 1113 i862571 Ob31743 7T0
9、 FOREWORD IT (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. Some 179 member countries, 84 telecom operating entities, 145 scientific and ind
10、ustrial organizations and 38 international organizations participate in ITU-T which is the body which sets world telecommunications standards (Recommendations). The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, 1993). In
11、 addition, the World Telecommunication Standardization Conference (WTSC), which meets every four years, approves Recommendations submitted to it and establishes the study programme for the following period. In some areas of information technology which fall within ITU-Ts purview, the necessary stand
12、ards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O ITU 1996 All rights reserved. No part of this publication may be
13、reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. 11 Recommendation 1.233.1 - Annex F (07/96) CONTENTS Page Annex F . Frame relay multicast F . 1 Introduction F.2 Definition F.3 Description
14、. F.3.1 General description . F.3.2 Specific terminology F.3.3 Qualifications . Service description . F.5.1 One-way multicast service F.5.2 Two-way multicast service . F.5.3 N-way multicast service . F.4 Multicast service model F . 5 F.6 Procedures F.6.1 Provisiodwithdrawal F.6.2 Normal procedures F
15、.6.3 Exceptional procedures . F.6.4 Alternate procedures F.6.5 Verification F.7 Interworking requirements . Multicast servers distributed across the NNI PVC management procedures for the NNI F.7.1 F.7.2 Recommendation 1.233.1 . Annex F (07196) 1 2 2 2 2 3 6 9 9 10 . 111 STD-ITU-T RECMN 1-233-1 ANNEX
16、 F-EMGL L7Ib El 4862571 Ub31715 573 m Recommendation 1.233.1 FRAME MODE BEARER SERVICES: ISDN FRAME RELAYING BEARER SERVICE Annex F Frame relay multicast (Geneva, 1996) F.l Introduction This annex describes optional multipoint configurations for the Frame Relaying Bearer Service. These configuration
17、s are known as Frame Relay Multicast. The definition and description of these configurations are the basis for defining the network capabilities required for the support of the service in an ISDN. Recommendation 1.233.1 describes the ISDN Frame Relaying Bearer Service. Recommendation X.6 was used as
18、 a basis for this annex. In some instances definitions have been modified to more appropriately fit the frame relay model. References - - CCITT Recommendation 1.233 (1991), Frame mode bearer services. CCITT Recommendation 1.233.1 (1 99 l), Frame mode bearer services: ISDNframe relaying bearer servic
19、e. - CCITT Recommendation 4.922 (1992), ISDN data link layer specijkation for pame mode bearer services. ITU-T Recommendation Q.933 (1 995), Signalling speczjcation for pame mode basic call control. - - CCITT Recommendation 1.370 (1991), Congestion management for the ISDN pame relaying bearer servic
20、e. ITU-T Recommendation 1.372 (1 993), Frame relaying bearer service network-to-network interface requirements. ITU-T X.6 (I 993), Multicast service depnition. - - F.2 Definition The multicast services provide the capability for frame relay service suppliers to offer point-to- multipoint frame deliv
21、ery services. The services in this annex are connection-oriented. That is, before a user of a multicast service is able to send or receive any multicast data, the user must first establish a connection (permanent virtual connection) to the multicast server. Recommendation 1.233.1 - Annex F (07/96) -
22、 1 STD-ITU-T RECMEJ 1-233-1 ANNEX F-ENGL LL P 48L259L Ub3179b 9OT F.3 Description F.3.1 General description This service description describes the frame relay multicast services from the user perspective. It addresses only the case where the multicast service is provided on a Permanent Virtual Conne
23、ction (PVC) and is configured by network administration. Multicast services on Switched Virtual Connections (SVCs) are for further study. Dynamic modifications to the multicast service configuration by the user is also for further study. In general, a frame relay data unit is addressed to a specific
24、 destination. When the data unit arrives at the destination, the address has been modified and is delivered with an address reflecting the senders return path. A multicast service may take advantage of this function and combine it with a copy function to allow a user to send a single message to mult
25、iple destinations. These destinations may reside on a single network or multiple networks. F.3.2 Specific terminology These terms are provided as a tool for better understanding of this annex, Some definitions, however, are complex and may not be fully defined here. In these cases, in order to restr
26、ict duplication of text, the term indicates a paragraph number to refer to for further explanation. . F.3.2.1 active group: The subset of a Multicast Group which is currently operational. (Refer to F.4) F.3.2.2 data link connection identifier (DLCI): It is the identifier of a frame relay connection.
27、 These values have only local significance. DLCI is defined in Annex NQ.922. F.3.2.3 frame relay multicast service: One in which a single data unit transmitted by a source is received by multiple destinations; it is a one-in, many-out service. F.3.2.4 leaf: A member of a one-way or two-way multicast
28、 group which receives multicast frames. F.3.2.5 multicast group: A set of members participating in a frame relay multicast service. F.3.2.6 member: A participant in a multicast group. F.3.2.7 multicast connection: A connection established by the service provider for the purpose of facilitating the s
29、ending of a single frame to multiple destinations. F.3.2.8 multicast DLCI (Mdlci): The DLCI assigned to designate a particular multicast connection at a particular frame relay access interface. F.3.2.9 one-way: A type of multicast service. (Refer to F.5.1.) F.3.2.10 root: The member of a one-way or
30、two-way multicast group which transmits multicast frames. F.3.2.11 two-way: A type of multicast service. (Refer to F.5.2.) F.3.2.12 N-way: A type of multicast service. (Refer to F.5.3.) F.3.2.13 station: A frame relay DTE. That is any machine (router, host, etc.,) that uses the services of a frame r
31、elay network. In the context of this annex, station does not refer to those devices that are a part of the frame relay network itself. F.3.3 Qualifications No restrictions have been identified. 2 Recommendation 1.233.1 - Annex F (07/96) F.4 Multicast service model Much of the multicast service model
32、 is taken directly fiom the X.6 Multicast Service Definition. This is a general purpose model and frame relay specifics are discussed in subsequent subclauses. The multicast service model shows a multicast group consisting of members that participate in a multicast communication using an intermediat
33、e entity called the multicast server. The multicast server is a logical entity which provides the multicast service to all members. Figure F.l illustrates the multicast service model. Station B Station A Station C Station D TO1 04610-95 FIGURE F. UI.233.1 Multicast service model The multicast server
34、 may be a centralized server as shown in Figure F.l or it may be a distributed service with several units providing the multicasting function. There is no limit to where the multicast servers reside (either internal to, or outside of the network) but for the purposes of discussion, the multicast ser
35、vers will be viewed as a single logical unit internal to the frame relay network. A multicast group is an entity that defines a domain in which members may participate in multicast communication and precludes communication with users not in the group. Each multicast group is independent of any other
36、 and therefore, a member of one multicast group may belong to other multicast group simultaneously. The set of members participating in multicast communications is called the active group and a member participating in a particular multicast group is called a participant. For example, in Figure F.l,
37、the active group consists of stations A, B, C, and D. If participant C leaves the group (loses connectivity or is removed from the multicast group), the active group becomes participants A, B, and D. F.5 Service description These multicast services, in general, provide the ability to establish a mul
38、ticast relationship between the members of a group and allow them to participate in point-to-multipoint data transfer. The data transfer occws only for the active group. That is, a multicast server receiving a data unit at time t, will deliver that unit to the members of the active group as of time
39、t. Members that join the active group (it may have been inactive before this time) after time t, may or may not receive the data unit. Recommendation 1.233.1 - Annex F (07/96) 3 STD-ITU-T RECMN 1-233-1 ANNEX F-ENGL 197b 48b2591 Oh31748 282 W There are three types of multicast service. All require a
40、one to many mapping of source to destination, but each requires the service provider to interpret the meaning of multiple destinations differently. These applications are described in the following subclauses. Note that the questions of where data unit duplication occurs, how address transformation
41、is performed, and how to provide multicasting are implementation issues and are not specified. The following descriptions are models only, and may or may not reflect actual implementations of a given multicast service. In general, it will not be useful for a participant sending data to receive a cop
42、y of its own transmission. Therefore, the multicast model assumes that the originator does not receive its own transmissions. This does not, however, exclude the possibility that some future application may wish to design a service in which the sender does receive its own transmissions. F.5.1 One-wa
43、y multicast service This multicast service requires that the root have point-to-point frame relay connections established to all leaves in the multicast group. The root will also maintain a separate one-way multicast connection to the multicast server. With this configuration, the root sends multica
44、st frames via the one-way multicast connection identified by a one-way multicast DLCI (Mdlci). The multicast server will accept frames from the Mdlci and will send the frame to each leaf member of the active multicast group. Additionally, when the multicast service is distributed across an NNI (see
45、F.7.1.2), the multicast server will also send the frame to the “NI Mdlci. Frames delivered in this manner arrive as though they were transmitted on the individual point-to-point connections established between the root and leaves. That is the DLCI (address) in the received frame reflects the source
46、of the message and will not retain the Mdlci (multicast address). FIGURE F.2I.233.1 One-way multicast For example, Figure F.2 shows the root, station A, with a single frame relay interface (station A may have other interfaces which are not shown here). The multicast group may be viewed logically as
47、the group of PVCs b, c, and d. The one-way multicast service will accept a frame on Mdlci from StationA and transmit it to each destination designated by the active multicast group. As these frames traverse the network, they are treated no differently than other frames and therefore, arrive at the d
48、estination stations as though they had been transmitted on each of the separate PVCs from Station A. Station B will receive the frame on its connection t, Station C on its connection u and Station D on its connection v. 4 Recommendation 1.233.1 - Annex F (07/96) STD-ITIJ-T RECMN 1.233-1 ANNEX F-ENGL
49、 L97L aP 4AL2591 Ob31749 II9 This service is useful in applications where the stations are routers or bridges. The multicast frame will typically be used for obtaining or verifying the presence or identification of the multicast group members. As defined, the Mdlci is a one-way DLCI. That is, frames are never sent fiom the network to the root on it. Frames transmitted on the Mdlci which arrive at Station B have no different characteristics from those frames sent from Station A on DLCI “b“. Frames from the one-way multicast group members to Station A are transm
