Together,
these five parameters specify the bandwidth profile for a particular service:
Bandwidth Profile =
Committed Information Rate (CIR) CIR is the average rate up to which service
frames are delivered as per the performance objectives (such as delay, loss, etc.) associated
with the service; these service frames are referred to as being CIR-conformant.
The CIR value is always less than or equal to the UNI speed15 and basically guarantees
that the specified amount of bandwidth (or service frames) will be delivered according
to a predetermined performance level. A CIR of zero indicates the service has
neither bandwidth nor performance guarantees.
NOTE Independent of the CIR, the service frames are always sent at UNI speed.
Committed Burst Size (CBS) CBS is the limit on the maximum number, or bursts,
of service frames in bytes allowed for incoming service frames so they are still CIRconformant.
Excess Information Rate (EIR) The EIR specifies the average rate, greater or equal
to the CIR, up to which service frames are admitted into the Service Provider network;
these frames are said to be EIR-conformant.
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