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DS queue with probabilities rTS/C and rDS/C, respectively.
5.3. Performances of BPR and BPR +
In the following simulation scenarios, we evaluate the ability of BPR scheduler to
provide proportional delay differentiation between the throughput-sensitive and delay-
sensitive class. We compare its performance with the performance of BPR + in order to
evaluate the performance improvement that could be achieved by considering arrival
times of backlogged packets.
The simulated topology in ns-2 network simulator [31] is shown in Fig. 11. There
are NTS=5 throughput-sensitive sources and NDS=5 delay-sensitive sources sending their
packets to the sink. All sources are ON/OFF Pareto sources with average packet size of
500 bytes, average durations of ON and OFF periods 50 ms, and shape parameter 1.5.
Capacities and propagation delays of links are indicated in Fig. 11. BPR and BPR + are
implemented in the access router R. The capacity of the output buffer in the router is 250
packets, except for the scenario where we vary the buffer size.
Fig. 11. Simulated topology used for evaluating the performances of BPR and BPR + .
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