Bandwidth Optimization Through Hybrid Codecs G.711 and G.729 for VoIP Ethernet, FR and MP Networks

Abstract

With the rapid growth in both internet and telecommunication technologies, VoIP has become more and more popular and expected to replace the traditional telephony services. The main issues in communication of real time application on IP networks, however, are providing high Quality of Service (QoS), security and appropriate capacity of transmission medium. Therefore, one of the most important factors to consider when designing packet voice networks is the capacity. This paper focuses on the capacity problem and attempts to determine the minimum bandwidth (BW) that can support in each transmission rate based on different speech codecs. In precise, this paper discusses an overhead problem in VoIP transmission and studies the extent of which the required BW is affected by the type of used network and the dependency on the codec type used for the VoIP encoders. The study devises the variation payload size in two codec techniques (G.711and G.729) to optimize the BW utilization. The study concluded that increasing the payload size and using the cRTP protocol would reduce bandwidth requirements to more than 50%.