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

The scheme requires no parameter settings.
Performance analysis with xed and variable ABR capacity.
The drawbacks of the scheme are:
The scheme does not measure the load (aggregate input rate) at the switch. As
a result, if a source is sending at a rate below its CCR, then the bottleneck will
be underutilized.
The scheme also does not observe the queuing delay at the switch. Errors in
estimation of ABR capacity result in errors in feedback andeventually result in
queues. Hence, there is a possibility of in nite queues if the queuing delay is not
considered as a metric. However, such a mechanism may easily be developed
on similar lines as the ERICA+ proposal studied later in the dissertation.
The scheme assumes that the sum of the number of bottlenecked and satis ed
connections is equal to the number of connections setup. The scheme does not
measure the number of active connections. As a result, if a connection is setup,
but remains idle for a while, the allocations to other connections remain low
and may result in underutilization.
The convergence time is slower since the scheme attempts never to over-allocate
(conservative). This non-optimistic strategy may result in link underutilization
of the sources are not always active, or cannot utilize their ER allocations [2].
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