serv") and RSVP [1] have developed extensions to the IP architecture and the best-effort service model so that applications or end users can request specific quality (or levels) of service from an internetwork in addition to the current IP best-effort service. Recent efforts in the Differentiated Services Working Group are also directed at the definition of mechanisms that support aggregate QoS services. The int-serv model for these new services requires eXPlicit signaling of the QoS (Quality of Service) requirements from the end points and provision of admission and traffic control at Integrated Services routers. The proposed standards for RSVP [RFC2205] and Integrated Services [RFC2211, RFC2212] are examples of a new reservation setup protocol and new service definitions respectively. Under the int-serv model, certain data flows receive preferential treatment over other flows; the admission control component only takes into account the requester's resource reservation request and available capacity to determine whether or not to accept a QoS request. However, the int-serv mechanisms do not include an important ASPect of admission control: network managers and service providers must be able to monitor, control, and enforce use of network resources and services based on policies derived from criteria such as the identity of users and applications, traffic/bandwidth requirements, security considerations, and time-
of-day/week. Similarly, diff-serv mechanisms also need to take into account policies that involve various criteria such as customer identity, ingress points, and so on.
This document is concerned with specifying a framework for providing policy-based control over admission control decisions. In particular, it focuses on policy-based control over admission control using RSVP as an example of the QoS signaling mechanism. Even though the focus of the work is on RSVP-based admission control, the document outlines a framework that can provide policy-based admission control in other QoS contexts. We argue that policy-based control must be applicable to different kinds and qualities of services offered in the same network and our goal is to consider such extensions whenever possible.
We begin with a list of definitions in Section 2. Section 3 lists the
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