Page 142 7750 SR OS Services Guide
A multi-service site must have a port scope defined that ensures all queues associated with the site are
on the same port or channel. If the scope is not set to a port, the agg-rate-limit command will fail.
Once an agg-rate-limit has been assigned to a multi-service site, the scope cannot be changed to card
level.
A port scheduler policy must be applied on the egress port or channel the SAP or multi-service site
are bound to in order for the defined agg-rate-limit to take effect. The egress port scheduler enforces
the aggregate queue rate as it distributes its bandwidth at the various port priority levels. The port
scheduler stops offering bandwidth to member queues once it has detected that the aggregate rate
limit has been reached.
If a port scheduler is not defined on the egress port, the queues are allowed to operate based on their
own bandwidth parameters.
The optional queue-frame-based-accounting keyword allows the service queues within the SAPs to
operate in the frame based accounting mode.
Once egress frame based accounting is enabled on a SAP or Multi-Service Site, all queues associated
with the SAP or SAPs will have their rate and CIR values interpreted as frame based values. When
shaping, the queues will include the 12 byte Inter-Frame Gap (IFG) and 8 byte preamble for each
packet scheduled out the queue. The profiling CIR threshold will also include the 20 byte frame
encapsulation overhead. Statistics associated with the queue will also include the frame encapsulation
overhead within the octet counters.
The queue-frame-based-accounting keyword does not change the behavior of the agg-rate-limit rate
value. Since agg-rate-limit is always associated with egress port based scheduling and egress port
based scheduling is dependant on frame based operation, the agg-rate-limit rate is always interpreted
as a frame based value.
The no form of the command removes the aggregate rate limit from the SAP or multi-service site.
Parameters {max | kilobits-per-second} — The max keyword and kilobits-per-second parameter are mutually
exclusive. Either max or a value for kilobits-per-second must follow the agg-rate-limit command.
max — The max keyword specifies that the egress aggregate rate limit for the SAP or the Multi-
Service Site is unlimited. Scheduling for the service queues will only be governed by the individual
queue parameters and any congestion on the port relative to each queues scheduling priority.
kilobits-per-second — The kilobits-per-second parameter defines an actual egress aggregate rate to
which all queues associated with the SAP or Multi-Service Site will be limited. The value must be
defined as an integer and is representative of increments of 1000 bits per second.
Values 1 to 40000000
Default max
queue-frame-based-accounting — This keyword enables frame based accounting on all queues
associated with the SAP or Multi-Service Site. If frame based accounting is required when an
aggregate limit is not necessary, the max keyword should precede the queue-frame-based-accounting
keyword. If frame based accounting must be disabled, execute agg-rate-limit without the queue-
frame-based-accounting keyword present.
Default Frame based accounting is disabled by default
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