Narrow Results

This paper presents a comparative analysis of call set up times, MOS (Mean Opinion Score), packet end to end delay and packet loss for the H.323 and SIP (Session Initiation Protocol) signaling schemes used in Voice Over IP (Voice over Internet Protocol) calls. We compare voice performance parameters like MOS, delay, jitter and call set up times and establish the differences in performance of these two VoIP protocols through an opnet simulation. This detailed simulation study is performed over H.323 and SIP networks where we have shown that the H.323 network performed better in terms of call set up time and packet end to end delay for the signaling messages. However, MOS for the voice packets in both the networks was expectedly the same as the same network topology was used for both the signaling protocols. There has been an influx of a large number of signaling and transport protocols over IP networks, giving rise to unacceptably large delays, most unsuitable for real time applications. SIP and H.323 are used for establishment and release of Voice aver IP calls as well as Video and Media calls. Both these protocols play a very important role in terms of optimizing the call set up time and call reliability and flexibility over IP networks for real time applications like voice and video.