The fairness
algorithm ensures weighted dynamic distribution of available link bandwidths to
source stations using those links.
The fairness procedure has the following characteristics:
?– Support independent fairness operation per ringlet.
?– Carry control information on the ringlet opposing that of the associated data
flow.
?– Regulate only classC and classB-EIR (i.e., fairness eligible) traffic.
?– Compute fair rates associated with a source station.
?– Scale fair rates in proportion to an administrative weight assigned to each fairness
instance.
?– Allow ringlet capacity not explicitly allocated to be treated as available capacity.
?– Allow ringlet capacity explicitly allocated to subclassA1 or classB-CIR, but not in
use, to be treated as available capacity (i.e., bandwidth reclamation).
?– Support either single transit queue or dual transit queue deployment.
?– Support either the aggressive or the conservative rate adjustment method.
Class of Service Quality of Service
Name Use Subclass
Guaranteed
Bandwidth Delay/Jill Bandwidth Type
Bandwidth
Subtype
ClassA Real-time subclassA0
SubclassA1
Yes Low Allocated Reserved
Reclaimable
ClassB Guaranteed classB-CIR
classB-EIR
Yes
No
Bounded
Unbounded
Allocated
Opportunistic
Reclaimable
ClassC Best-effort No Unbounded Opportunistic Reclaimable
TABLE 12.
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