This method enables a series of rate limits to be applied to packets. Cascading specifies more granular policies to match packets against an ordered sequence of policies until an applicable rate limit is reached, and the packet is either transmitted or discarded. Packets that fall to the bottom of a list of rate limits are transmitted. You can configure up to 100 rate policies on a subinterface.
CAR can be used to partition network traffic into multiple priority levels or classes of service (CoSs). You may define up to eight CoSs using the three precedence bits in the Type of Service field in the IP header, and then utilize the other QoS features to assign appropriate traffic-handling policies, including congestion management, bandwidth allocation, and delay bounds for each traffic class. In particular, CAR may be used to apply this policy at the perimeter of the network, leaving WRED to appropriately deal with packets within the core and distribution networks.
The status of traffic shaping can be examined using the show traffic, show traffic statistics, and show <interface> rate-limit commands.
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