BS ISO/IEC TR 13243:1999 - Page 2

Information technology. Quality of service. Guide to methods and mechanisms. | Status: Current

1 Scope This Recommendation | Technical Report uses the concepts and terminology of the Quality of Service Framework, ITU-T Rec. X.641 | ISO/IEC 13236. It is intended to support those designing, testing and specifying Information Technology (IT) systems, data communications services and protocols, those defining QoS management functions and QoS mechanisms for particular data environments and technologies, and those engaged in other QoS-related activities such as system testing, by providing a source of reference material on QoS. To do this, it brings together references to methods and mechanisms from a variety of sources, and in some cases documents them in a style which will permit their use in many data different environments. The term "method" is used in a very general sense to include any process, function, etc., that is relevant to QoS at any stage in the life-cycle of a system. The criterion for reference to or inclusion of definitions or specifications of QoS methods and mechanisms in this Recommendation | Technical Report is that they are thought to be of potentially wider application than solely the environment for which they were originally developed, although still in a data context. Clause 5 identifies sources of definitions of QoS characteristics and related information. Clauses 6, 7 and 8 discuss methods and mechanisms appropriate to the phases of QoS activity that are defined in the QoS Framework: clause 6 deals with the prediction phase, clause 7 with the establishment phase and clause 8 with the operational phase. Clause 9 describes methods for verification of system behaviour related to QoS. Clause 10 covers the relationships between this Recommendation | Technical Report and Recommendations, International Standards or Technical Reports that reference it. This Recommendation | Technical Report contains detailed definitions of some QoS mechanisms. Some peer-to-peer QoS negotiation mechanisms are defined in 7.1.1. These involve two peer entities and in most cases also the provider of a communications service between them. Subclause 7.1.2 provides an initial specification of some QoS negotiation mechanisms for 1 × N multicast connections, based on those in 7.1.1. Subclause 7.1.3 discusses QoS negotiation mechanisms for M × N multicast, some of which can make use of those in 7.1.2. Subclause 8.2.1 defines some QoS management mechanisms to support time-critical applications. This Recommendation | Technical Report does not include methods and mechanisms for security.