Design and Analysis of Queue Control Functions for Explicit Rate Switch Schemes

摘要

The main goals of a switch scheme are high utilization, low queuing delay andfairness. To achieve high utilization the switch scheme can maintain non-zero(small) queues in steady state which can be used if the sources do not havedata to send. Queue length (delay) can be controlled if part of the linkcapacity is used for draining queues in the event of queue build up. In mostschemes a simple threshold function is used for queue control. Better controlof the queue and hence delay can be achieved by using sophisticated queuecontrol functions. It is very important to design and analyze such queuecontrol functions. We study step, linear, hyperbolic and inverse hyperbolicqueue control functions. Analytical explanation and simulation resultsconsistent with analysis are presented. From the study, we conclude thatinverse hyperbolic is the best control function and to reduce complexity thelinear control function can be used since it performs satisfactorily in mostcases.