Consolidated Platform Configuration Guide, Cisco Ios Release 15.2(4)E (Catalyst 2960-X Switches - Cisco Catalyst 2960 series Configuration Manual
Consolidated platform configuration guide, ios release 15.2(4)e
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Also See for Catalyst 2960 series:
- Software configuration manual (980 pages) ,
- Command reference manual (800 pages) ,
- Configuration manual (120 pages)
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• Aggregate—QoS applies the bandwidth limits specified in an aggregate policer cumulatively to all
matched traffic flows. You configure this type of policer by specifying the aggregate policer name within
a policy map by using the police aggregate policy-map class configuration command. You specify the
bandwidth limits of the policer by using the mls qos aggregate-policer global configuration command.
In this way, the aggregate policer is shared by multiple classes of traffic within a policy map.
Policing uses a token-bucket algorithm. As each frame is received by the switch, a token is added to the bucket.
The bucket has a hole in it and leaks at a rate that you specify as the average traffic rate in bits per second.
Each time a token is added to the bucket, the switch verifies that there is enough room in the bucket. If there
is not enough room, the packet is marked as nonconforming, and the specified policer action is taken (dropped
or marked down).
How quickly the bucket fills is a function of the bucket depth (burst-byte), the rate at which the tokens are
removed (rate-bps), and the duration of the burst above the average rate. The size of the bucket imposes an
upper limit on the burst length and limits the number of frames that can be transmitted back-to-back. If the
burst is short, the bucket does not overflow, and no action is taken against the traffic flow. However, if a burst
is long and at a higher rate, the bucket overflows, and the policing actions are taken against the frames in that
burst.
You configure the bucket depth (the maximum burst that is tolerated before the bucket overflows) by using
the burst-byte option of the police policy-map class configuration command or the mls qos aggregate-policer
global configuration command. You configure how fast (the average rate) that the tokens are removed from
the bucket by using the rate-bps option of the police policy-map class configuration command or the mls qos
aggregate-policer global configuration command.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
Information About QoS
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