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

y the four conditions: x>0andy>0 and U(1 + ) x + y U(1 ; ) Observe
that x and y are strictly greater than zero. The case of x = 0 or y = 0 reduces the
number of sources to one.
Similarly, when the network is operating in a region close to the fairness line,
we consider the network to be operating fairly. This region is bounded by the lines
corresponding to y = x(1 ; )=(1 + ) and y = x(1 + )=(1 ; ). The quadrangular
region bounded by these two lines in side the TUB is called the fairness region. This is
shown in Figure 5.24(b). Mathematically, theconditions de ning the fairness region
are:
(1 + )
x y
(1 ; )
(1 ; )
x (5.1)
(1+ )
U(1 + ) x + y U(1 ; ) (5.2)
The fair share s is U=2. Recall that the TUB algorithm sets the load adjustment
factor (LAF) as follows:
words,
IF (x 0 and y s and U(1 + ) x + y U(1 ; )
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