RFC 2753 (rfc2753) - Page 2 of 20
A Framework for Policy-based Admission Control
Alternative Format: Original Text Document
RFC 2753 Framework for Policy-based Admission Control January 2000
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
requirements and goals of the mechanisms used to control and enforce
access to better QoS. We then outline the architectural elements of
the framework in Section 4 and describe the functionality assumed for
each component. Section 5 discusses example policies, possible
scenarios, and policy support needed for those scenarios. Section 6
specifies the requirements for a client-server protocol for
communication between a policy server (PDP) and its client (PEP) and
evaluates the suitability of some existing protocols for this
purpose.
2. Terminology
The following is a list of terms used in this document.
- Administrative Domain: A collection of networks under the same
administrative control and grouped together for administrative
purposes.
- Network Element or Node: Routers, switches, hubs are examples of
network nodes. They are the entities where resource allocation
decisions have to be made and the decisions have to be enforced. A
RSVP router which allocates part of a link capacity (or buffers)
to a particular flow and ensures that only the admitted flows have
access to their reserved resources is an example of a network
element of interest in our context.
In this document, we use the terms router, network element, and
network node interchangeably, but the should all be interpreted as
references to a network element.
- QoS Signaling Protocol: A signaling protocol that carries an
admission control request for a resource, e.g., RSVP.
Yavatkar, et al. Informational