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

A combination of several ideas in a scheme which achieves the essential goals of
fast convergence to fair shares and control of queues.
An O(1) approximation of the MIT scheme idea, combined with the tracking of
load through the exponential averaging of the ERmax variable.
Some of the drawbacks of the scheme are:
The calculation of feedback at the receipt of both the forward and backward
RM cells increases the computation burden on the switch.
The setting of ER in both directions may inhibit rate increase for one round
trip time (when the backward direction feedback using the latest information
cannot increase the rate because the forward direction had commanded a rate
decrease).
The use of exponential averaging of rates is not entirely correct because a)
the rates are ratios and averaging of ratios should be done carefully [49], b)
the successive values of rates used in the averaging may not be correlated.
In general, Exponential averaging does not produce good results if the values
averaged do not exhibit correlation.
4.12 HKUST Scheme
4.12.1 Key Techniques
This scheme was developed by researchers Tsang and Wong at the Hong Kong
University of Science and Technology (HKUST). The scheme is a modi cation of
the MIT scheme, which retains the O(N) computational complexity and marks the
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