AN END CONNECTED DQDB WITH ERASURE NODES

Abstract

Distributed Queue Dual Bus (DQDB) is a Media Access control (MAC) protocol which .is being standardized as an IEEE 802.6 Metropolitan Area Network (MAN).This dissertation implements an alternative solution that can improve network fairness and also a new topology, "An end connected DQDB with erasure nodes". This is suitable for very high speed MANS's. Fairness is improved using slot reuse method, which is implemented using erasure node algorithm. This method also remove stale request from distribute request queue. The end connected DQDB with erasure node further improve throughput by utilizing slots generally free at ends. Thus end connected DQDB with erasure nodes will considerably improve throughput and fairness. Like DQDB, end connected DQDB achieves full throughput efficiency independent of the bus length, the transmission speed and number of nodes. Unlike - DQDB, end connected DQDB with erasure nodes allocate equal - bandwidth under heavy load to all active users in a time period less than or equal to round trip propagation delay without wasting bandwidth