A Comparative Evaluation of Space Priority Strategies in ATM Networks

Current standards reserve one bit in the ATM cell header to indicate loss priority. When congestion occurs ai a queue lower priority cells can be discarded in order to insure a smaller cell loss rate for higher priority cells. Strategies for determining which cells to discard are termed space priority buffer management schemes. In ihis paper two adjustable space priority schemes are studied, where a cell upon arriving to a full buffer can pushout a cell of opposite priori ty depending upon an adjustable pmmeter . A queueing analysis of an ATM switching node is conducted to compare the adjustable pushout schemes with other common space priority mechanisms.