engleski

An Evaluation of ABR Explicit-rate Allocation Interfering with the Guaranteed Services Traffic

In this paper operation of two recently proposed ABR explicit-rate schemes is evaluated in the presence of variable background traffic of the guaranteed services. Influence of variable target utilization and switch averaging interval on the system performance is analyzed. In our previous work a transient behaviour of the explicit-rate allocation, for the single-node case, is analyzed by analytical and simulation models. Herby we present simulation results for both single and multiple-node networks, with performance metrics including link utilization, queue length, and allocation fairness. From the obtained results it could be concluded that for both, single and multiple node networks, a higher switch averaging interval improves allocation fairness. It is also found that ERICA+ scheme proves to be very robust and is not susceptible upon set parameters. It ensures a transient queue build-ups avoidance and preserves high link utilization. The EDERA scheme provides more precise rate allocation and relatively low average queue legth, resulting in the link under-utilization. It is shown that a larger switch averaging interval combined with a variable target utilization function provides better allocation performance.

available bit rate; explicit rate allocation; congestion avoidance; discrete-event simulation

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