Packet dispersion and the quality of voice over IP applications in IP networks

Next generation networks (NGN) and the migration towards IP networks is likely to make the IP technology the main vehicle for earning voice and video calls on modern networks. Packet dispersion is a mechanism by which the packets of a certain session are dispersed over multiple paths, in contrast to the traditional approach by which they follow a single path most of the time. In this work we examine the quality of voice over IP (VoIP) applications and the effects of packet dispersion on it. We focus on the effect of the network loss on the applications, where we propose to use noticeable loss rate (NLR) as a measure correlated with the voice quality. We analyze the NLR for various packet dispersion strategies over paths experiencing memory-less (Bernoulli) or bursty (Gilbert model) losses, and compare them to each other. Our analysis reveals, that in many situations, in particular for most cases where losses are bursty, the use of packet dispersion reduces the NLR and thus improves session quality. The results suggest that the use of packet dispersion can be quite beneficial for these applications.