Experimental study on QoS provisioning to heterogeneous VoIP sources in Diffserv environment

The work presents a research activity focused on the experimental study of three different issues related to the provision of VoIP services with QoS guarantee in DiffServ networks. Firstly the study deals with the analysis of two dissimilar strategies for the setting of the parameters of a traffic control module in a DiffServ network node. Using these results, secondly the effectiveness of static and dynamic SLAs strategies for QoS provisioning in DiffServ environment is experimentally evaluated. This analysis is carried out considering aggregation of voice sources adopting two distinct codecs, i.e. G723.1 and G729. These codecs produce traffic with different statistical features (variable and constant bit rate respectively). Hence, this approach allows assessing the impact on the single sources´ performance of the multiplexing of heterogeneous VoIP sources in a single class.