Performance Analysis of Packet Telephony over LANs

Abstract

The framework of multimedia communications over LANs with non-guaranteed quality-of service (QoS) has been proposed in H.323, which has been applied to a variety of multimedia communications, including LANs as well as MANs, WANs, enterprise networks and the Internet through gateway interfaces. The main body of H.323includes the specification of the real-time transport protocol (RTP) and the RTP control protocol (RTCP) for real-time applications over Internet. It is essential to offer the quality-of service (QoS) of packet telephony on smoothing the bursty traffic over real-time packet transmission in LANs since the media often were rendered unintelligibly due to delay jitters. This paper studies the performance of packet telephony in terms of packet delay and packet loss probability over the CSMA/CD LANs. Results of the analysis show that in a CSMA/CD LAN environment, packet telephony services still maintain a higher trunking efficiency than that in T1 under the conditions that a certain level of packet delay and loss probability is tolerated and a suitable voice compression technology, such as G.729 and GSM, is adopted.