Performance evaluation of the dynamic system for codecs management: DY.CO.MA

Nowadays, the traditional telephone service has experienced deep changes in the years concerning the techniques of commutation and signaling. Private integrated services networks (PINSs) are strongly directed to adopt IP-based backbone becoming virtual private networks (VPN). Using voice over IP (VoIP) protocols requires the transmission of voice by means of IP packets. This means that the coding of voice in IP packets is one of the main aspects to analyze and optimize in order to establish reliable transmission with adequate quality of service. We assume that the starting codec selection phase has a predominant effect on global network performance, and needs more accurate studies by VoIP researchers. We consider a dynamic codec management (DY.CO.MA) strategy, which aims to maintain a high call admission rate without reducing quality voice performance, measured by some specific quality indicative indexes. This paper is mainly focused on the management of coding technique inside VoIP to improve network performance and utilization in a simulated VPN scenario, where many VoIP proposed solutions interact all together. New modules have been added to network simulator 2 (NS2) to perform simulations.