Chapter 6 QOS

Quality of service (QOS) is use to improve the network efficiency. ERT-805 provides some different QOS, which are CAR, Policy-based Routing, Weight fair queuing and class-map

6.1 CAR – Committed Access Rate

CAR (Committed Access Rate) is allows user to limit the output transmission rate on an interface. CAR provides two qualities of service functions:

ØBandwidth management through rate limit

ØPacket classification through IP precedence

The following example is shows how to configuration CAR:

rate-limit output [access-group]access-list no bps Normal bust number Maximum bust number conform-actionconform action exceed-actionexceed action – configure CAR and distributed policies.

 

 

 

 

output

Applies this CAR traffic policy to packets sent on this output

interface.

 

 

 

 

 

access-group

(Optional) Applies this CAR traffic policy to the specified access

list.

 

 

 

 

 

bps

Average rate, in bits per second (bps).

 

 

 

 

Normal burst bytes

Normal burst size, in bytes.

 

 

 

 

Maximun bust bytes

Excess burst size, in bytes.

 

 

 

 

conform-action

∙ continue—Evaluates the other rate-limit

∙ drop—Drops the packet.

conform-action

∙ transmit—Sends the packet.

 

 

 

 

 

 

∙ continue—Evaluates the other rate-limit .

exceed-action exceed-action

∙ drop—Drops the packet.

 

∙ transmit—Sends the packet.

 

 

 

 

 

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