1、 International Telecommunication Union ITU-T X.608.1TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2008) SERIES X: DATA NETWORKS, OPEN SYSTEM COMMUNICATIONS AND SECURITY OSI networking and system aspects Networking Information technology Enhanced communications transport protocol: Specification
2、 of QoS management for n-plex multicast transport Recommendation ITU-T X.608.1 ITU-T X-SERIES RECOMMENDATIONS DATA NETWORKS, OPEN SYSTEM COMMUNICATIONS AND SECURITY PUBLIC DATA NETWORKS X.1X.199 OPEN SYSTEMS INTERCONNECTION X.200X.299 INTERWORKING BETWEEN NETWORKS X.300X.399 MESSAGE HANDLING SYSTEMS
3、 X.400X.499DIRECTORY X.500X.599 OSI NETWORKING AND SYSTEM ASPECTS Networking X.600X.629 Efficiency X.630X.639 Quality of service X.640X.649 Naming, Addressing and Registration X.650X.679 Abstract Syntax Notation One (ASN.1) X.680X.699 OSI MANAGEMENT X.700X.799 SECURITY X.800X.849 OSI APPLICATIONS X.
4、850X.899 OPEN DISTRIBUTED PROCESSING X.900X.999 INFORMATION AND NETWORK SECURITY X.1000X.1099 SECURE APPLICATIONS AND SERVICES X.1100X.1199 CYBERSPACE SECURITY X.1200X.1299SECURE APPLICATIONS AND SERVICES X.1300X.1399 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T
5、 X.608.1 (11/2008) i INTERNATIONAL STANDARD ISO/IEC 14476-6 RECOMMENDATION ITU-T X.608.1 Information technology Enhanced communications transport protocol: Specification of QoS management for n-plex multicast transport Summary This Recommendation | International Standard describes quality of service
6、 (QoS) management functions for the n-plex multicast transport over Internet where IP multicast is supported. Quality of service (QoS) management functions such as QoS negotiation, monitoring and maintenance features are specified. Protocol details such as packet format, parameter values and procedu
7、res are described. This protocol can be used for applications that require many-to-many data delivery service with QoS managing facility; the protocol is expected to provide transport service to multimedia conference service over IP multicast, etc. Source Recommendation ITU-T X.608.1 was approved on
8、 13 November 2008 by ITU-T Study Group 11 (2009-2012) under Recommendation ITU-T A.8 procedure. An identical text is also published as ISO/IEC 14476-6. ii Rec. ITU-T X.608.1 (11/2008) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of te
9、lecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing tele
10、communications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the
11、procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a
12、telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of
13、 these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS
14、 ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU m
15、embers or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may
16、 not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T X.6
17、08.1 (11/2008) iii CONTENTS Page 1 Scope . 1 2 Normative references 1 3 Definitions 1 3.1 Terms defined in Rec. ITU-T X.605 | ISO/IEC 13252 1 3.2 Terms defined in Rec. ITU-T X.606 | ISO/IEC 14476-1 1 3.3 Terms defined in Rec. ITU-T X.606.1 | ISO/IEC 14476-2 . 2 3.4 Terms defined in Rec. ITU-T X.608
18、| ISO/IEC 14476-5 2 4 Abbreviations 2 4.1 Packet types. 2 4.2 Miscellaneous 3 5 Conventions 3 6 Overview 3 7 Components for QoS management. 5 7.1 Base header 5 7.2 QoS parameters 6 7.3 QoS extension element. 7 7.4 Error bitmap element . 9 7.5 Packets used for QoS management . 9 7.6 Packet format . 1
19、0 8 Procedures for QoS management . 11 8.1 QoS negotiation 11 8.2 QoS monitoring 13 8.3 QoS maintenance 15 9 Timers and variables . 17 9.1 Timers 17 9.2 Operation variables 17 Annex A Implementation considerations 19 A.1 A scenario of interworking between ECTP-6 and RSVP . 19 Bibliography . 21 iv Re
20、c. ITU-T X.608.1 (11/2008) Introduction ECTP is designed to support tightly controlled multicast connections in simplex, duplex and n-plex applications. This part of ECTP (Recommendation ITU-T X.608.1 | ISO/IEC 14476-6) specifies the quality of service (QoS) management functions for the n-plex multi
21、cast transport protocol (ECTP-5: Recommendation ITU-T X.608 | ISO/IEC 14476-5). In the n-plex multicast connection, the participants include one TC-Owner and many TS-users. TC-Owner will be chosen among the TS-users before the connection begins. TC-Owner is at the heart of multicast group communicat
22、ions. It is responsible for overall connection management by governing the connection creation and termination, multicast data transport, and the late join and leave operations. The multicast data transmissions are allowed by TS-users as well as the TC-Owner. Each TS-user is allowed to send multicas
23、t data to the group only if it gets a token from the TC-Owner. That is, the multicast data transmissions of TS-users are controlled by the TC-Owner. For the stable QoS management of the n-plex multicast connection, this Specification provides the QoS management functions such as QoS negotiation, QoS
24、 monitoring and QoS maintenance. The target QoS parameters are negotiated between the TC-Owner and TS-users before the connection creation. During the connection, the status of the connection is monitored by TS-users, and the monitoring result is delivered to Sending TS-users and the TC-owner via co
25、ntrol packets. According to the QoS monitoring result, Sending TS-users may adjust their data transmission rate, and the TC-owner may pause or terminate the connection. This QoS management Specification can be used in multicast applications that want to support various QoS requirements and the corre
26、sponding billing/charging models. ISO/IEC 14476-6:2010 (E) Rec. ITU-T X.608.1 (11/2008) 1 INTERNATIONAL STANDARD RECOMMENDATION ITU-T Information technology Enhanced communications transport protocol: Specification of QoS management for n-plex multicast transport 1 Scope This Recommendation | Intern
27、ational Standard provides a specification of QoS management for accomplishing a desired quality of service in n-plex multicast transport connections. For this purpose, this Specification describes the QoS management operations in n-plex multicast transport connections such as QoS negotiation, QoS mo
28、nitoring and QoS maintenance. This Recommendation | International Standard is an integral part of ECTP-5 (Rec. ITU-T X.608 | ISO/IEC 14476-5). All of the protocol components, including packet formats and protocol procedures specified in Rec. ITU-T X.608 | ISO/IEC 14476-5, are also valid in this Reco
29、mmendation | International Standard. 2 Normative references The following Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated we
30、re valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and
31、 ISO maintain registers of currently valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid ITU-T Recommendations. Recommendation ITU-T X.601 (2000), Multi-peer communications framework. Recommendation ITU-T X.602 (2004) | ISO/IEC 1
32、6513:2005, Information technology Group management protocol. Recommendation ITU-T X.605 (1998) | ISO/IEC 13252:1999, Information technology Enhanced Communications Transport Service Definition. Recommendation ITU-T X.606 (2001) | ISO/IEC 14476-1:2002, Information technology Enhanced Communications T
33、ransport Protocol: Specification of simplex multicast transport. Recommendation ITU-T X.606.1 (2003) | ISO/IEC 14476-2:2003, Information technology Enhanced Communications Transport Protocol: Specification of QoS management for simplex multicast transport. Recommendation ITU-T X.607 (2007) | ISO/IEC
34、 14476-3:2008, Information technology Enhanced communications transport protocol: Specification of duplex multicast transport. Recommendation ITU-T X.608 (2007) | ISO/IEC 14476-5:2008, Information technology Enhanced communications transport protocol: Specification of N-plex multicast transport. 3 D
35、efinitions 3.1 Terms defined in Rec. ITU-T X.605 | ISO/IEC 13252 This Recommendation | International Standard is based on the concepts developed in Enhanced Communications Transport Service (Rec. ITU-T X.605 | ISO/IEC 13252): a) QoS parameters; b) QoS negotiation; c) QoS arbitration. 3.2 Terms defin
36、ed in Rec. ITU-T X.606 | ISO/IEC 14476-1 This Recommendation | International Standard is described based on the concepts and terms developed in the specification of simplex multicast transport on ECTP-1 (Rec. ITU-T X.606 | ISO/IEC 14476-1): a) application; b) packet; ISO/IEC 14476-6:2010 (E) 2 Rec.
37、ITU-T X.608.1 (11/2008) c) sender; d) receiver; e) tree; f) parent; g) child. 3.3 Terms defined in Rec. ITU-T X.606.1 | ISO/IEC 14476-2 This Recommendation | International Standard is described based on the concepts and terms developed in the specification of simplex multicast transport on ECTP-2 (R
38、ec. ITU-T X.606.1 | ISO/IEC 14476-2). a) QoS monitoring; b) QoS maintenance. 3.4 Terms defined in Rec. ITU-T X.608 | ISO/IEC 14476-5 This Recommendation | International Standard is described based on the concepts and terms developed in the specification of n-plex multicast transport on ECTP-5 (Rec.
39、ITU-T X.608 | ISO/IEC 14476-5). a) TCN (TC-Owner): An n-plex multicast connection has a single TCN. The TCN is responsible for connection management including connection creation/termination, late join, connection maintenance, and token management. For example, in teleconferencing applications, the
40、TCN may act as the conference server, which may be used for control of the conferencing without sending multicast data. In the example of a multi-user on-line game application, the TCN may act as the game-control server. b) SU (Sending TS-user): A TS-user who gets a token from the TCN. Only the SU i
41、s allowed to send multicast data to the group. In other words, before sending multicast data, each user must request a token from the TCN. c) LO (Local Owner): For a given subset of participants, an LO becomes a root of a locally configured shared tree in the local group. Each LO is also connected t
42、o other LOs in inter-group trees. Each LO will control the tree configuration for the local group. It will also perform error recovery as the parent for the local group. d) Token: It represents the right for a TS-user to transmit multicast data. A TS-user who has a token is called an SU. The tokens
43、are managed by the TC-Owner. e) Multicast data channel: The TCN or an SU can send multicast data to all the other group members over an IP multicast address. 4 Abbreviations For the purposes of this Recommendation | International Standard, the following abbreviations apply: 4.1 Packet types ACK Ackn
44、owledgment CC Connection Creation Confirm CR Connection Creation Request CSR Connection Status Report CT Connection Termination Request DT Data JC Late Join Confirm JR Late Join Request TGC Token Get Confirm TGR Token Get Request ISO/IEC 14476-6:2010 (E) Rec. ITU-T X.608.1 (11/2008) 3 TSR Token Stat
45、us Report 4.2 Miscellaneous ADN Active Descendant Number CHQ Controlled Highest Quality Diffserv Differentiated Services ECTP Enhanced Communications Transport Protocol ECTS Enhanced Communications Transport Services IP Internet Protocol LQA Lowest Quality Allowed MSS Maximum Segment Size OT Operati
46、ng Target QoS Quality of Service RSVP Resource Reservation Protocol 5 Conventions None. 6 Overview This Recommendation | International Standard provides a specification of QoS management for n-plex multicast transport connections. This Specification describes the following QoS management operations:
47、 a) QoS negotiation, including reservation of network resources: For QoS negotiation, this Specification assumes that a desired QoS level for multicast application service can be expressed in terms of a set of QoS parameters. QoS negotiation is performed via an exchange of control packets between th
48、e TCN (TC-owner) and TS-users for the multicast data channel. The TCN proposes the target values of QoS parameters obtained from the applications requirements in order for TS-users to send or receive multicast data, and each TS-user can propose modified values based on its system and/or network capa
49、city and the applications requirements. The TCN arbitrates the modified values proposed by TS-users. Target values for QoS parameters can be used as input parameters for reservation of network resources. b) QoS monitoring: QoS control in ECTP-6 is based on feedback of control packets from TS-users. The feedback messages from TS-users enable the TCN to keep track of the number of TS-users and also to monitor the connection status for the multicast data channel. QoS monitoring is designed to allow TS-users and the TCN to diagnose
