The 7705 SAR supports egress-rate limiting and ingress-rate limiting on Ethernet ports.
The egress rate is set at the port level in the config>port>ethernet context.
Egress-rate limiting sets a limit on the amount of traffic that can leave the port to control the total bandwidth on the interface. If the egress-rate limit is reached, the port applies backpressure on the queues, which stops the flow of traffic until the queue buffers are emptied. This feature is useful in scenarios where there is a fixed amount of bandwidth; for example, a mobile operator who has leased a fixed amount of bandwidth from the service provider.
The ingress-rate command configures a policing action to rate-limit the ingress traffic. Ingress-rate enforcement uses dedicated hardware for rate limiting; however, software configuration is required at the port level (ingress-rate limiter) to ensure that the network processor or the adapter card or port never receives more traffic than they are optimized for.
The configured ingress rate ensures that the network processor does not receive traffic greater than this configured value on a per-port basis. Once the ingress-rate value is reached, all subsequent frames are dropped. The ingress-rate limiter drops excess traffic without determining whether the traffic has a higher or lower priority.