CANOGA PERKINS 9145E NID Software Version 4.10 - Manual (Page 280)

9145E NID Software User’s Manual Bandwidth Profiling
Bandwidth Profiles
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• Excess Information Parameters:
• Excess Information Rate (EIR) is expressed in Kbits per second. It defines the
average rate in Kbits of service frames up to which the network may deliver ser-
vice frames, but without any performance objectives. EIR must be greater than or
equal to 0. EIR must be multiple of 64Kbit/s, or 1Mbit/s. EIR can be 0 only if EBS
is also zero and CIR and CBS are not zero.
• Excess Burst Size (EBS) is expressed in Kbytes. It limits the maximum number of
Kbytes available for a burst of Service Frames sent at the line speed to conform to
EIR. This represents the maximum amount of tokens in the EIR token bucket.
EBS accepts an input range of 10-254 in increments of 2. When EBS is 0, EIR
must also be zero and CIR and CBS cannot be zero.
• a Coupling Flag (CF), which allows the choice between two modes of operation of the
rate enforcement algorithm. It determines whether excess tokens from the CIR bucket
can be put into the EIR bucket. It must have only one of two possible values, 0 or 1. For
the 9145E, the value of the coupling flag is 0.
• The Color Mode parameter, which indicates whether the color-aware or color-blind prop-
erty is employed by the Bandwidth Profile. It takes a value of color-blind or color-aware
only. In the case of the 9145E, this value is color-blind for the policers and color-aware
for the shapers. This is read-only attribute.
• A reference counter, indicating the number of policers or shapers using the profile. Only
profiles that are not in use can be deleted or modified.
Up to 127 policer bandwidth profile records can be stored on a 9145E system.
The BWP algorithm is illustrated in Figure 13-1. There are two buckets: the C bucket and the E
bucket. These buckets get filled at a rate determined by CIR and EIR, respectively. The C
bucket has a depth of CBS and the E bucket has a depth of EBS.
If the Coupling Flag is enabled and the C bucket overflows with tokens, these excess tokens will
be transferred to the E bucket. In this manner, the Coupling Flag can control the amount of
frames that get marked yellow by the system.
NOTE: The Coupling Flag is set to Disabled for release 4.10.