An Effective Erasure Node Algorithm for Slot Reuse in DQDB

The Ihstnbuted Queue Dual Bus (DQDB) protocol, wliich has been specified by the IEEE 802 6 ;is the Metropolitan Area Networks (MANS) standard, has an undesirable feature that busy slots that has been alreadb received ( I e read) continue to propagate d0wti:;tre'Wl riiinecessarily The use of special nodes, known as erasure nodes. allows conversion of read slots to empty, so that downstream nodes niay reus(; these slots This rjhould result in ai increase of thr total throughput of the network In this paper, we introduce and evaluate the perforiliaice ot an erasure node ;iIj:oritlun The algorithm keeps track of past activities on both busses to effectively balance the clot erasure 'and the request cancellation functions We show that this algorithm possesses ;L iiuiiibt.r of features which make it superior to existing nl-ori t hili s