1、 International Telecommunication Union ITU-T Y.1563TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2009) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Quality of service and network performance Ethernet frame transfe
2、r and availability performance Recommendation ITU-T Y.1563 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.
3、300Y.399 Interfaces 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, networ
4、k capabilities and 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 fu
5、nctional architecture 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 m
6、anagement Y.2400Y.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.1563 (01/2009) i Recommendation ITU-T Y.1563 Ethernet frame transfer and availa
7、bility performance Summary Recommendation ITU-T Y.1563 defines parameters that may be used in specifying and assessing the performance of speed, accuracy, dependability and availability of Ethernet frame transfer of an Ethernet communication service. The defined parameters apply to end-to-end, point
8、-to-point connections and multipoint connectivity in the Ethernet layer 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. Source Recommendation ITU-T Y.1563 was approved on 13 January 2009 by I
9、TU-T Study Group 12 (2009-2012) under Recommendation ITU-T A.8 procedures. ii Rec. ITU-T Y.1563 (01/2009) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU T
10、elecommunication 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 telecommunications on a worldwide basis. The World Telecommunication Standardizati
11、on 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 procedure laid down in WTSA Resolution 1. In some areas of information technol
12、ogy 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 telecommunication administration and a recognized operating agency. Compliance
13、 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 these mandatory provisions are met. The words “shall“ or some other obligato
14、ry 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 ITU draws attention to the possibility that the practice or implementation o
15、f 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 members or others outside of the Recommendation development process. As of the
16、 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 not represent the latest information and are therefore strongly urged to con
17、sult 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 the prior written permission of ITU. Rec. ITU-T Y.1563 (01/2009) iii CONTENTS Page 1 Scope 1 2 References. 3 3 Definitions 4 3.1
18、 Terms defined elsewhere 4 3.2 Terms defined in this Recommendation. 4 4 Abbreviations and acronyms 5 5 Conventions 6 6 Layered model of performance for Ethernet service 6 7 Ethernet service performance model, reference events and outcomes. 7 7.1 Network components 7 7.2 Links and network sections 7
19、 7.3 Measurement points and measurable sections 8 7.4 Ethernet frame transfer reference events (FREs) . 8 7.5 Ethernet frame transfer outcomes. 10 7.6 Frame qualifications . 13 8 Ethernet frame transfer performance parameters . 14 8.1 Point-to-point Ethernet frame transfer delay (FTD). 15 8.2 Point-
20、to-multipoint Ethernet frame transfer delay . 18 8.3 Ethernet frame error ratio (FER) 20 8.4 Ethernet frame loss ratio (FLR) 20 8.5 Spurious Ethernet frame rate 22 8.6 Frame rate-related parameters 22 8.7 Comparison with objectives (general calculation for all point-to-multipoint parameters) 23 8.8
21、Organization of parameters according to use case . 23 9 Ethernet service availability . 23 9.1 Severe errored second (SESETH). 23 9.2 Criteria for entry to and exit from unavailable state. 24 9.3 Ethernet service availability parameters. 24 Annex A Secondary terminology for assessing delay variation
22、 . 25 A.1 Introduction 25 A.2 Definition of IP packet delay variation 25 A.3 Definition of inter-frame delay variation (IFDV) for Ethernet frame transfer 25 A.4 Summarizing IFDV performance. 26 A.5 Areas for further study 26 iv Rec. ITU-T Y.1563 (01/2009) Page Appendix I Implications of sampling lar
23、ge groups. 27 I.1 Introduction 27 I.2 Performance at sample destinations . 27 Appendix II Alternative parameters using the framework of this Recommendation . 28 II.1 Introduction 28 II.2 Point-to-multipoint performance parameters . 28 II.3 Relationship to other standards 29 Appendix III Harmonizing
24、terminology for frame delay and frame delay variation metrics 30 III.1 Introduction 30 III.2 Frame delay and frame delay variation 30 III.3 Inter-frame delay variation. 31 III.4 Concatenation of inter-frame delay variation. 31 Appendix IV Networking technologies making use of Ethernet 33 Appendix V
25、OAM measurement considerations 34 V.1 Introduction 34 V.2 Loss performance based on counters 34 Appendix VI Mapping to Recommendation ITU-T G.8010 terms and conventions (and to those of other associated Recommendations). 35 VI.1 Introduction 35 VI.2 Mapping between Ethernet network performance and a
26、rchitecture Recommendations 35 VI.3 In-service measurement and applicability of performance and availability parameters. 37 Bibliography. 39 Rec. ITU-T Y.1563 (01/2009) 1 Recommendation ITU-T Y.1563 Ethernet frame transfer and availability performance 1 Scope This Recommendation defines parameters t
27、hat may be used in specifying and assessing the performance of speed, accuracy, dependability and availability of Ethernet frame transfer on an Ethernet network. It provides a simple set of constructs (terms, definitions and illustrations) and the semantics that allow the performance parameters to b
28、e applied to Ethernet networks in many useful ways. This Recommendation describes Ethernet networks in terms of basic sections, such as networks and links, and measurement points at the boundaries between them. These descriptive terms and concepts have been developed and refined over a series of Rec
29、ommendations addressing various networking technologies (e.g., ATM, IP, MPLS), and applied to Ethernet technology in this Recommendation. Ethernet networks described using these basic sections (and a few well-known concepts in the networking industry) can be related to Ethernet layer networks define
30、d in ITU-T G.8010 (architecture of Ethernet layer networks) and Ethernet services defined in b-ITU-T G.8011. ITU-T G.8010 provides a functional specification of Ethernet bridges as defined in b-IEEE 802.1D and b-IEEE 802.1Q. Appendix VI provides the relationship. The defined parameters apply to netw
31、orks that provide, or contribute to the provision of, Ethernet services in accordance with the normative references specified in clause 2. It applies to point-to-point Ethernet topologies and to point-to-multipoint Ethernet topologies. Multipoint-to-multipoint topologies which add a greater level of
32、 complexity are left for further study. The scope of this Recommendation is summarized in Figure 1. The Ethernet network performance parameters are defined on the basis of Ethernet frame transfer reference events that may be observed at measurement points (MPs) associated with specified functional a
33、nd jurisdictional boundaries. For comparability and completeness, Ethernet network performance is considered in the context of the 3 3 performance matrix defined in b-ITU-T I.350. Three protocol-independent communication functions are identified in the matrix: access, user information transfer and d
34、isengagement. Each function is considered with respect to three general performance concerns (or “performance criteria“): speed, accuracy and dependability. An associated two-state model provides a basis for describing Ethernet network availability. Access and disengagement phases are beyond the sco
35、pe of this Recommendation. In particular, additional Ethernet frames associated to MAC learning procedures are not considered in this Recommendation, since they are related to the access phase. 2 Rec. ITU-T Y.1563 (01/2009) Y.1563(09)_F01NetworksectionMP MPEthernet networkBridgeBridgeBoundary Bounda
36、ryETHframeETHframeETHframeETHframeMP Measurement pointMP MPBridgeor DSTETHframeETHframeETHframeETHframeBoundary BoundaryExchangelinkBridgeor SRCLinkY.1563 Ethernet frame transfer reference eventsY.1563 Ethernet frame transferperformance parameters(Clause 7)(Clause 8)CriterionFunctionAccessUser infor
37、mationtransferDisengagementEthernet serviceunavailableY.1563 availabilityparametersSpeed Accuracy DependabilityEthernet serviceavailable(Clause 9)Figure 1 Scope of this Recommendation The objectives associated with the Ethernet user information transfer performance parameters are for further study.
38、Another Recommendation will specify these performance objectives. The end-to-end performance of Ethernet networks providing access and disengagement functions and higher-layer transport capabilities (e.g., Internet Protocol) may be addressed in separate Recommendations. This Recommendation is struct
39、ured as follows: Clause 1 specifies its scope. Clause 2 specifies its normative references. Clause 3 lists the terms used and/or defined in this Recommendation. Clause 4 provides a list of abbreviations. Clause 6 illustrates the layered model that creates the context for Ethernet performance specifi
40、cation. Clause 7 defines the model used for Ethernet performance, including network sections and measurement points, reference events and outcomes. Clause 8 uses this model to define Ethernet frame transfer performance parameters. Clause 9 then defines Ethernet service availability parameters. Appen
41、dix I describes the implications of sampling large multicast groups on performance parameters definitions and possibly the associated objectives. Appendix II provides alternative parameters which use the framework of point-to-point parameters at registered destinations of a multicast group defined i
42、n this Recommendation. Appendix III proposes to harmonize terminologies for frame delay and frame delay variation metrics developed by ITU-T and MEF. Appendix IV describes different networking opportunities making use of Ethernet technology. Finally, Appendix V presents OAM measurement consideration
43、s, and Appendix VI addresses the mapping to alternate descriptive terms for Ethernet architectures in ITU-T G.8010. NOTE 1 The speed, accuracy and dependability parameters of this Recommendation are intended to characterize Ethernet service in the available state. Rec. ITU-T Y.1563 (01/2009) 3 Howev
44、er, no measurements of these parameters made during periods of unavailable time are ever used for determining long-term frame transfer performance, and mechanisms must be established to exclude all performance measurement results collected during unavailable periods from any estimations of long-term
45、 Ethernet frame performance parameters. NOTE 2 The parameters of this Recommendation are designed to characterize the performance of service provided by network elements between specified section boundaries. However, users of this Recommendation should be aware that network elements outside the spec
46、ified boundaries can sometimes influence the measured performance of the elements between the boundaries. NOTE 3 The parameters defined in this Recommendation can also be applied to any subset of the Ethernet frames offered to a given set of network equipment. Methods for aggregating performance ove
47、r a set of network equipment or over an entire network are outside of the scope of this Recommendation. NOTE 4 The word “provisional“, as used in this Recommendation, means that there is agreement on the stability of the value referenced, but that the value may change following further study, or on
48、the basis of real network operational experience. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommend
49、ations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying 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. ITU-T G.805 Recommendation ITU-T G.805 (2000), Generic functional architecture
