A Dimensioning Strategy for Almost Guaranteed Quality of Service in Voice over IP Networks

Providing hard quality of service guarantees for Voice over IP traffic in multi-service IP networks is quite costly in terms of network resources. However, if one is willing to slightly soften the guarantees and to accept a small probability of service degradation, the amount of capacity necessary for voice traffic can be greatly reduced. In this paper, we investigate the tradeoff between quality of service and the required bandwidth for voice traffic in IP networks taking into account different scheduling schemes. We propose a dimensioning strategy, which allows the worst-case packet delay to exceed a desired threshold with a certain probability. Based on simulations, it can be demonstrated that bandwidth is reduced while the quality of service is assured in most cases.