31-4 Riverstone Networks RS Switch Router User Guide Release 8.0
Creating a Service Service Configuration
Both the credit count and the replenish rate are calculated by the RS according to the rate-limiting profile defined in
the configuration. The RS uses a special algorithm to determine the best credit count and replenish rate to achieve
optimum bandwidth control.
Figure31-1 shows the operation of the hardware credit bucket.
Figure 31-1 Hardware credit buckets
All credit validation is performed locally in the line card. The control module only becomes involved when a new entry
needs to be created in the hardware. It programs the entry in the ASICs on the line card, then subsequent packets are
handled locally.
31.2.2 Flow-Aggregate Rate Limiting Service
Flow-aggregate rate limiting can be used on line cards that are not enabled for aggregate rate limiting. It can also be
used on cards that do not support aggregate rate limiting. If aggregate rate limiting is enabled on a particular line card,
per-flow rate limiting policies can not be applied to ports on that line card.
To create a flow-aggregate rate limiting service, use the following command:
Create a flow-
aggregate rate
limiting service.
service <name> create rate-limit flow-aggregate rate <rate>
[exceed-action <drop-packets | set-priority-low | set-priority-medium |
set-priority-high> min-bandwidth <minbw> distribute-among <distribute> |
time-select <num>]
Full Hardware
Credit Bucket
Empty Hardware
Credit Bucket
Drop packets
or
re-prioritize to
lower priority
or
change ToS precedence