1、 International Telecommunication Union ITU-T Y.1544TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (07/2008) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Quality of service and network performance Multicast IP performan
2、ce parameters Recommendation ITU-T Y.1544 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.200Y.299 Network aspects Y.300Y.399 Interfac
3、es and protocols Y.400Y.499 Numbering, addressing and naming Y.500Y.599 Operation, administration and maintenance Y.600Y.699 Security Y.700Y.799 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.1199 Architecture, access, network capabilities an
4、d resource management Y.1200Y.1299 Transport Y.1300Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 NEXT GENERATION NETWORKS Frameworks and functional architec
5、ture models Y.2000Y.2099 Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Numbering, naming and addressing Y.2300Y.2399 Network management Y.2400Y
6、.2499 Network control architectures and protocols Y.2500Y.2599 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Y.1544 (07/2008) i Recommendation ITU-T Y.1544 Multicast IP performance parameters Summary Recomme
7、ndation ITU-T Y.1544 extends the framework of Recommendation ITU-T Y.1540 to the point-to-multipoint, or multicast case. It also expands the key Y.1540 concepts with details needed to define parameters for the point-to-multipoint configuration. The performance of point-to-multipoint packet transfer
8、to a set of destinations can first be considered a set of point-to-point packet transfers, and characterized using any or all of the point-to-point parameters found in Recommendation ITU-T Y.1540. This Recommendation defines parameters that are specific to the point-to-multipoint case. There are thr
9、ee general categories of point-to-multipoint parameters which focus on different entities in this network topology: parameters that describe the Source performance, parameters that describe the performance at one or more Destinations, and parameters that can be applied to describe the performance of
10、 subsections of the multicast tree. In its present version, this Recommendation primarily addresses Destination performance. This Recommendation also specifies a complete set of parameters for the access and disengagement phases of communication. This aspect goes beyond the scope of Recommendation I
11、TU-T Y.1540, which covers only the information transfer phase. Source Recommendation ITU-T Y.1544 was approved on 14 July 2008 by ITU-T Study Group 12 (2005-2008) under Recommendation ITU-T A.8 procedure. ii Rec. ITU-T Y.1544 (07/2008) FOREWORD The International Telecommunication Union (ITU) is the
12、United Nations specialized agency in the field of telecommunications, 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 Recom
13、mendations on them with a view to standardizing telecommunications 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
14、approval of ITU-T Recommendations is covered by the 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 “Adminis
15、tration“ is used for conciseness to indicate both a 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 compli
16、ance with the Recommendation is achieved when all of 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
17、 required of any party. INTELLECTUAL PROPERTY RIGHTS 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 Int
18、ellectual Property Rights, whether asserted by ITU members 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 Recommendatio
19、n. However, implementers are cautioned that this may 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 2009 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without
20、 the prior written permission of ITU. Rec. ITU-T Y.1544 (07/2008) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Abbreviations and definitions. 2 3.1 Abbreviations . 2 3.2 Definitions 3 4 Multipoint considerations for the layered model of performance for IP service 4 5 Multipoint considerations for t
21、he generic IP service performance model 4 6 Multipoint IP packet transfer performance parameters 4 6.1 Populations of interest and group Membership 5 6.2 Loss-related parameters 7 6.3 Burst loss or outage-related parameters . 8 6.4 Delay-related parameters 8 6.5 Delay variation-related parameters. 9
22、 6.6 Packet rate-related parameters 9 6.7 Packet duplication and replication parameters. 10 6.8 Comparison with objectives (general calculation for all parameters) 10 6.9 Organization of parameters according to use case . 10 7 Point-to-multipoint IP service availability parameters. 11 8 Multicast gr
23、oup membership performance parameters 11 8.1 Reference events at the Destination UNI . 12 8.2 Communication access parameters. 12 8.3 Communication disengagement parameters. 13 9 Summary of performance parameters defined in this Recommendation 14 Appendix I Implications of sampling large groups. 15
24、I.1 Introduction 15 I.2 Performance at sample destinations . 15 Appendix II Alternative parameters using the framework of this Recommendation . 16 II.1 Introduction 16 II.2 Point-to-multipoint performance parameters . 16 Bibliography 18 Rec. ITU-T Y.1544 (07/2008) 1 Recommendation ITU-T Y.1544 Multi
25、cast IP performance parameters 1 Scope This Recommendation defines parameters that may be used in specifying and assessing the performance of speed, accuracy, dependability, and availability of IP packet transfer of international Internet protocol (IP) data communication services. The parameters app
26、ly to point-to-multipoint IP service and to the network portions that provide, or contribute to the provision of, such service in accordance with the normative references specified in clause 2. In particular, this Recommendation relies on the same layered model and generic performance model defined
27、in ITU-T Y.1540 for point-to-point communication. The scope of this Recommendation extends ITU-T Y.1540 to an area that was left for further study: point-to-multipoint communication. The scope of this Recommendation also includes performance parameters that are relevant to specific multicast protoco
28、ls. The protocols currently covered are versions 2 and 3 of the Internet group management protocol. Inclusion of these protocols expands beyond the scope of ITU-T Y.1540 to cover the access and disengagement communication functions. The operation of multicast routing protocols is evident to users an
29、d their hosts, primarily in terms of the networks ability to deliver packets from sources to destinations. This Recommendation does not specify performance parameters for these protocols. Table 1 illustrates the coverage of this Recommendation, in terms of the 3-by-3 matrix (defined in ITU-T I.350).
30、 Table 1 Partial scope of this Recommendation Criterion Function Speed Accuracy Dependability Access Multicast group membership performance parameters (clause 8) User information transfer Multipoint packet transfer performance parameters (clause 6) Disengagement Multicast group membership performanc
31、e parameters (clause 8) As stated above, the topic of availability is also included in the scope of this Recommendation. The reader of this Recommendation should be familiar with the concepts and definitions of ITU-T I.350 and ITU-T Y.1540. The outline of this Recommendation follows the outline of Y
32、.1540 to the extent possible, in order to simplify references and comparisons. Therefore, the unique multicast access and disengagement material appears near the end of the body of this Recommendation. 2 References The following ITU-T Recommendations and other references contain provisions which, th
33、rough reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applyin
34、g the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. 2 Rec. I
35、TU-T Y.1544 (07/2008) ITU-T I.350 Recommendation ITU-T I.350 (1993), General aspects of quality of service and network performance in digital networks, including ISDNs. ITU-T Y.1540 Recommendation ITU-T Y.1540 (2007), Internet protocol data communication service IP packet transfer and availability p
36、erformance parameters. IETF RFC 3376 IETF RFC 3376 (2002), Internet Group Management Protocol, Version 3. IETF RFC 3513 IETF RFC 3513 (2003), Internet Protocol Version 6 (IPv6) Addressing Architecture. 3 Abbreviations and definitions 3.1 Abbreviations This Recommendation uses the following abbreviat
37、ions: A(Tav) Fraction of destinations in the available state during TavCRE Commence Reference Event EnNumber of errored packet outcomes at destination n EL Exchange Link ER Edge Router FnNumber of lost spurious outcomes at destination n IGMP Internet Group Management Protocol IP Internet Protocol IP
38、v4 Internet Protocol Version 4 IPv6 Internet Protocol Version 6 IPDR IP packet Duplicate Ratio IPDV IP packet Delay Variation IPER IP packet Error Ratio IPLR IP packet Loss Ratio IPOR Octet-based IP packet rate IPPR IP Packet rate IPRE IP packet transfer Reference Event IPRR IP packet Reordered Rati
39、o IPSLBR IP packet Severe Loss Block Ratio IPTD IP packet Transfer Delay ISP Internet Service Provider JRE Join Reference Event Ln Number of lost packet outcomes at destination n LL Lower Layers, protocols and technology supporting the IP layer LRE Leave Reference Event Rec. ITU-T Y.1544 (07/2008) 3
40、 Mav The minimum number of packets recommended for assessing the availability state MP Measurement Point NS Network Section NSE Network Section Ensemble PDV Packet Delay Variation PIM Protocol Independent Multicast PMO Percent Meeting Objective Rn Number of successful packets at Destination n, with
41、respect to a population of interest Rmax Maximum number of successful packets at all Destinations in a group, max(Rn) S The number of packets a Source transmits that constitute the population of interest Tav Minimum length of time of IP availability; minimum length of time of IP unavailability Tmax
42、Maximum IP packet delay beyond which the packet is declared to be lost TJmax Waiting time for completion of an IGMP Join operation TLmax Waiting time for confirmation of an IGMP Leave TPOI Interval of time corresponding to transmission of the population of interest TR,n Interval corresponding to rec
43、eption of the population of interest at destination n Tr Result-recording time interval (availability) TRE Termination Reference Event 3.2 Definitions The primary purpose of this Recommendation is to define new terms and performance parameters. Most of the new terms appear in the clauses where they
44、are defined in detail. 3.2.1 Terms defined elsewhere This Recommendation extends ITU-T Y.1540 to the point-to-multipoint topology, all terms and performance parameters defined in ITU-T Y.1540 apply here as well. 3.2.2 Terms defined in this Recommendation This Recommendation defines the following ter
45、ms: 3.2.2.1 joining or leaving a multicast group: The process to add (or remove) a member from a multicast group. 3.2.2.2 multicast group: A multicast group is a set of hosts that have indicated their intention to receive packets on a specific multicast group address. This set of hosts and their ass
46、ociated egress measurement points provide a key qualification to the point-to-multipoint population of interest. 3.2.2.3 multicast group address: This is a destination address that allows potentially any host to receive packets of this group from a multicasting source host. In IPv4, a multicast grou
47、p address is a special destination address range (224.0.0.0/4), historically known as Class D. The best current practice for IPv4 multicast address assignment may be found in b-IETF RFC 3171. In IPv6, multicast addresses all have the prefix FF00:/8. Address assignments within this range are specifie
48、d in IETF RFC 3513. 3.2.2.4 permissible multicast group egress measurement points: One or more egress measurement points may be designated permissible when the Source to Destination path of at least 4 Rec. ITU-T Y.1544 (07/2008) one member of a multicast group includes that specific egress point, an
49、d the minimum set of egress points to cover all group members are identified. 4 Multipoint considerations for the layered model of performance for IP service The layered model for IP service (clause 4 of ITU-T Y.1540) also applies to the point-to-multipoint case. The only additional performance-related consideration is the reproduction of packets in multicast routers. When required, a multicast router is required to reproduce the packets of a given multicast group, to send them on two or more egress links toward their dest
