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ITU-T Y.1563

Ethernet frame transfer and availability performance

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Organization: ITU-T
Publication Date: 1 January 2009
Status: active
Page Count: 48
scope:

This Recommendation defines parameters that 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 be 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 Recommendations 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 defined 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 networks 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 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 and 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 disengagement. 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 scope 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.

The objectives associated with the Ethernet user information transfer performance parameters are for further study. 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 structured 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 specification. 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. Appendix 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 in 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 considerations, 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.

However, 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 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 specified 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 over 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 the basis of real network operational experience.

Document History

June 1, 2021
Ethernet frame transfer and availability performance Corrigendum 1
A description is not available for this item.
December 1, 2009
Ethernet frame transfer and availability performance Amendment 1: New Annex B – Terminology for consecutive severely errored seconds in Ethernet services
This Recommendation defines parameters that may be used in specifying and assessing the performance of speed, accuracy, dependability and availability of Ethernet frame transfer on an Ethernet...
ITU-T Y.1563
January 1, 2009
Ethernet frame transfer and availability performance
This Recommendation defines parameters that may be used in specifying and assessing the performance of speed, accuracy, dependability and availability of Ethernet frame transfer on an Ethernet...

References

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