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

scheme. Simple con gurations not only save time but also are more instructive in
nding problems than complex con gurations.
The con gurations are presented later in this section in the order in which we use
them repeatedly during design phase. For each design alternative, we always start
with the simplest con guration and move to the next only if the alternative works
satisfactorily for the simpler con gurations.
5.5.1 Default Parameter Values
Unless speci ed otherwise, we assume all links are 1 km long running at 155 Mbps.
The in nite source model is used for tra c initially. The burst tra c is considered in
Section 5.7. The averaging interval of 300 s and a target utilization band of 90(1
0.1)% is used.
5.5.2 Single Source
Figure 5.10: Single source con guration
This con guration shown in Figure 5.10 consists of one VC passing through two
switches connected via a link. This con guration was helpful in quickly discarding
many alternatives. Figure 5.11 shows plots for TCR, link utilization, and queue length
at the bottleneck link. Notice that there are no oscillations.
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