An architecture and admission control algorithm for multi-precedence voice over IP (VoIP) calls

Packet networks provide an environment where different types of network applications like voice and video would converge in a common physical network infrastructure. For the military networks, convergence may prove beneficial since this would enable the easy implementation of rich multimedia applications such as voice and data. Voice over IP (VoIP) is a technology that enables the transmission of voice over an IP network. A challenging task for the commercial application of VoIP is the fact that classical IP networks do not provide quality of service (QoS) guarantees that voice transmission requires. This requirement is even more important in the military environment since these networks carry mission-critical communication. In addition, military networks need to support different levels of voice precedence classes such that each class may see a different call blocking probability and high precedence calls may preempt lower precedence calls if the network resources are not adequate for both. In this paper, we introduce a novel QoS architecture and a measurement-based call admission control algorithm that supports quality of service for multiple voice classes. The algorithm uses link utilization measurements to derive call blocking decisions. The performance modeling results suggest that our proposed solution can limit the packet loss ratio, and hence guarantee voice QoS, even during major traffic overloads.