Traffic Management for the Available Bit Rate (ABR) Service in ...

5.5.3 Two Sources
Figure 5.12: Two-source con guration
This con guration helps study the fairness. It is similar to the single source con-
guration except that now there are two sources as shown in Figure 5.12. Figure 5.13
shows the con guration and plots for TCR, link utilization, and queue length at the
bottleneck link. Notice that both sources converge to the same level.
5.5.4 Three Sources
As shown in Figure 5.14, this is a simple con guration with one link being shared
by three sources. The purpose of this con guration is to check what will happen if
the load is such that the link is operating e ciently but not fairly. The starting rates
of the three sources are speci cally set to values that add up to the target cell rate for
the bottleneck link. Figure 5.15 shows the simulation results for this con guration.
5.5.5 Transient Sources
In order to study the e ect of new sources coming in the network, we modi ed
the two-source simulation such that the second source comes on after one third of the
simulation run and goes o at two third of the total simulation time. The speed at
which the TCRs of the two sources decrease and increase to the e cient region can
be seen from Figure 5.16.
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