A measurement-based admission control algorithm for VoIP

We propose an admission control algorithm for voice over Internet protocol (VoIP) calls and present the results of an extensive performance evaluation study. The proposed algorithm operates in VoIP gateways and rejects call requests when congestion is indicated in the path to the specified destination gateway The algorithm derives the network congestion information from the call quality reports received from the current real-time transport protocol (RTP) connections between the source and destination gateways. The performance of the algorithm has been investigated using simulation experiments and the results show very low packet loss ratios (PLRs) for the voice calls. Moreover, the call blocking ratio is very similar to that of an ideal call admission control that knows the exact number of calls at every network link. (C) 2003 Lucent Technologies Inc.