Transport and link layer performance comparison of CSMA/CD, token bus and token ring networks

Abstract

By means of experimental measurements, a comparative study is made on OSI transport and datalink layer performance in order to determine the relative merits of CSMA/CD, token bus and token ring networks. The results show that, by and large, token ring gives the best performance, both at datalink and transport interfaces. Of the other two networks, token bus performs better at transport layer, whereas CSMA/CD is capable of yielding higher throughput at datalink layer. Detailed analysis of throughput and end-to-end delay shows that the datalink service is two-times more efficient than the transport service. The difference gives the protocol penalty for providing reliable message delivery. The efficiency of the transport service is made worse by message segmentation, which contributes substantially to overall message latency. A study of the use of window credit confirms that it is an effective tool for controlling the data flow.