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 apply 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 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-tomultipoint communication.

The scope of this Recommendation also includes performance parameters that are relevant to specific multicast protocols. 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 and their hosts, primarily in terms of the network's 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]).

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.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.