RFC 3260 (rfc3260) - Page 2 of 10
New Terminology and Clarifications for Diffserv
Alternative Format: Original Text Document
RFC 3260 New Terminology and Clarifications for Diffserv April 2002 specifying classifier rules and any corresponding traffic profiles and metering, marking, discarding and/or shaping rules which are to apply...." As work progressed in Diffserv (as well as in the Policy WG [6]), it came to be believed that the notion of an "agreement" implied considerations that were of a pricing, contractual or other business nature, as well as those that were strictly technical. There also could be other technical considerations in such an agreement (e.g., service availability) which are not addressed by Diffserv. It was therefore agreed that the notions of SLAs and TCAs would be taken to represent the broader context, and that new terminology would be used to describe those elements of service and traffic conditioning that are addressed by Diffserv. - A Service Level Specification (SLS) is a set of parameters and their values which together define the service offered to a traffic stream by a DS domain. - A Traffic Conditioning Specification (TCS) is a set of parameters and their values which together specify a set of classifier rules and a traffic profile. A TCS is an integral element of an SLS. Note that the definition of "Traffic stream" is unchanged from RFC 2475. A traffic stream can be an individual microflow or a group of microflows (i.e., in a source or destination DS domain) or it can be a BA. Thus, an SLS may apply in the source or destination DS domain to a single microflow or group of microflows, as well as to a BA in any DS domain. Also note that the definition of a "Service Provisioning Policy" is unchanged from RFC 2475. RFC 2475 defines a "Service Provisioning Policy as "a policy which defines how traffic conditioners are configured on DS boundary nodes and how traffic streams are mapped to DS behavior aggregates to achieve a range of services." According to one definition given in RFC 3198 [6], a policy is "...a set of rules to administer, manage, and control access to network resources". Therefore, the relationship between an SLS and a service provisioning policy is that the latter is, in part, the set of rules that express the parameters and range of values that may be in the former. Further note that this definition is more restrictive than that in RFC 3198. Grossman Informational
