Interprocess communication dependency on network load

Results of an analysis of the communication performance as perceived by the application layer in the presence of background load are presented. The analysis was carried out on two distinct protocol suites, TCP/IP and XNS, on a single Ethernet LAN with personal computer workstations. Service times for a reliable transfer and an unreliable transmission as perceived by the application layer were measured. An appropriate model of the reliable transfer process was used to derive service time analytical estimates. Owing to the close relation between measured and estimated values, the model was used to identify the major sources of delay and to evaluate the effects of possible improvements. The most important causes affecting the transport layer performance as background load increases are identified, and different strategies are examined in order to reduce their impact. The improvement margin offered by the implementation of a lightweight transport protocol specifically tailored to the requirements of a bulk data transfer over an Ethernet is addressed