A performance study of a CSMA/CD ethernet with connected data link(s)

The Ethernet is a baseband local area network (LAN) which uses digital signaling and Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocol to control the network access. An Ethernet's shared communication facility, its Ether, is a passive broadcast medium with no central control. In Ethernet as the messages grow in number, many collide and only a small fraction of the true communications bandwidth is used for valid data. And, as more stations are connected, less and less data gets through, and the result is continuous collisions. Therefore, as traffic increases, the uncertainty of data delivery increases. This thesis asserts that a combination of Ethernet and an arbitrary number of direct data links (Hybrid-Ethernet) will significantly improve the network performance. The results indicate, even with small increase in link cost by addition of direct data links, LAN performance can be improved significantly over a pure Ethernet.