A measurement study of two local area network data link level protocols

Two protocols for the data-link level of local area networks, namely, the original Ethernet protocol and the EnetII protocol, are compared under varying load conditions. The two protocols were implemented on a testbed network. The protocols were found to have similar throughput and delay characteristics under normal network conditions, while Enet III achieved higher throughput and greater stability under extreme overload conditions. The predicted delay advantage for Enet II was not observed in these measurements due to implementation compromises, but Enet II was observed to achieve its goal of greatly reducing the variance of the packet queuing delay. It was also noted that, contrary to previously reported results, network utilization is sensitive to the number of traffic-producing hosts, for five or more hosts