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.
- Policy: The combination of rules and services where rules define the criteria for resource access and usage.
- Policy control: The application of rules to determine whether or not access to a particular resource should be granted.
- Policy Object: Contains policy-related information such as policy elements and is carried in a request or response related to a resource allocation decision.
- Policy Element: Subdivision of policy objects; contains single units of information necessary for the evaluation of policy rules.
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