REAL TIME PERFORMANCE STUDY OF MULTIPLE RING TOKEN LANs

Abstract

During the past few years, the token ring technique has emerged as an important technology for local area networking. It has many advantages over other LAN techniques. However, at higher transfer rates (i.e., > 200 Mbps) with the simple token ring protocol, the available bandwidth is not utilized properly. So, the high speed ring is split into several low speed rings. The resulting network is called multiple ring network. This thesis comprises the study of the performance of various medium access protocols used in multiple ring networks through simulation. The performance data presented in this study is the maximum observed message delay and the percentage of messages missing their deadlines. These performance measures are more relevant to any real time work load. One of the most important real time problems is that of integrating voice and data onto a single network. Both of them have different characteristics and require different kind of service from the network. So an attempt has been made to integrate voice and data traffic onto the multiple ring network. Typical performance parameters considered are percentage of voice packets transmitted, data packet delay and percent network utilisation. The simulation software is written in "C" language and runs in UNIX environment.