A Call Admission Control Method for Supporting Telephony Sessions in a Best Effort IP Network

Abstract

An actively studied research area of the past couple of years is the design of connection admission control techniques for IP networks. This paper proposes a new, end-to-end measurement based approach for call admission control in IP telephony gateways. The method relies on measuring the quality experienced by ongoing live sessions: it collects packet loss and delay statistics about the sessions active between peer telephony gateways. This leads to very fast admission decision compared to existing methods, and also eliminates the signalling load and the maintenance of associated flow state in the core routers. The paper contributes to answering the fundamental question of what sort of QoS guarantees can be provided by a core-stateless QoS provisioning architecture, and it also investigates the effect of flows subjected to end-to-end measurement based admission control on legacy TCP traffic.