Resource Admission Control – Overview of Relevant Standards
|Publication Date:||1 February 2010|
SCOPE AND PURPOSE
The key principle driving resource and admission control is relatively straightforward and can be stated in the following three steps:
1. Determine the requirements for the call/session seeking admission into the network. Examples of such requirements include bandwidth, Quality of Service (QoS), and priority. These requirements are determined by the service type. For example, an Emergency Telecommunications Service (ETS) call would require the highest priority for admission control and stringent bandwidth requirements for acceptable voice quality.
2. Determine the availability of resources in the transport layer in order to support the requirements of the incoming call/session.
3. If the available resources can accommodate the minimum requirements, admit the call/session, else deny1.
In practice however, this process can be complex. The evolution towards "Next Generation Networks" (NGN) includes a combination of networking technologies (e.g., Ethernet, wireless, MPLS) and encompasses wireless and wire-line convergence. At the same time, new service offerings include various combinations of real-time, packet data, and multimedia services provided by an IP Multimedia Subsystem (IMS) environment.
Service providers may chose to offer certain types of services over "Private Networks" such as MPLSbased Virtual Private Networks (VPN). Alternately, they may design their networks as "Public Networks" - or "Shared Networks" - to support a wide variety of services whereby individual services compete for resource allocation during the admission process.
This Technical Report provides a high level examination of the current state of the work on resource and admission control being advanced in various Standards Development Organizations (SDO) and the challenges in implementing practical admission control solutions over Private or Public Network environments.
1 Service providers may also have provisions for admitting calls/sessions at lower QoS requirements to with appropriate charging fees. These options depend on the Service Level Agreement established with the customer.