Call Routing with Weighted Random Selection and Endpoint Admission Control for VOIP Traffic

VoIP has been widely investigated to provide statistical quality of service (QoS) guarantees. We address the issue of how to select an efficient route to carry real-time traffic. Each eligible route is assigned a weight, which is updated according to network level QoS evaluation. When a new coming call arrives, originating signaling server first chooses two candidate routes from all practicable routes based on their weights. Then it executes endpoint measurement based admission control on the two routes to evaluate their QoS. The route with better performance is selected to carry VoIP traffic. Simultaneously, all weights of routes are self-adjusted based on the new collected network condition information. Simulation results confirm that weighted random selection based call routing algorithm achieves better statistical QoS guarantee than other methods in terms of end-to-end delay and call blocking ratio, with help of enhanced admission control.