3com S7906E Instruccion De Instalación

 

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When configuring traffic classification, traffic policing, and traffic shaping, go to these sections for 

information you are interested in: 

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Traffic Policing, Traffic Shaping, and Line Rate Overview 

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Configuring Traffic Policing 

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Without limits on user traffic, a network can be overwhelmed very easily. To help assign network 

resources such as bandwidth efficiently to improve network performance and hence user satisfaction, 

QoS technologies such as traffic policing, traffic shaping, and rate limit were introduced. For example, 

you can configure a flow to use only the resources committed to it in a certain time range, thus avoiding 

network congestion caused by burst traffic.  

Traffic policing and generic traffic shaping (GTS) limit traffic rate and resource usage according to traffic 

specifications. Once a particular traffic exceeds its specifications such as bandwidth assigned to it, it is 

shaped or policed to ensure that it is under the specifications. Generally, token buckets are used to 

evaluate traffic specifications.  

A token bucket is analogous to a container holding a certain number of tokens. The system puts tokens 

into the bucket at a set rate. When the token bucket is full, the extra tokens overflows.  

The evaluation of traffic specifications is based on whether the number of tokens in the bucket can 

meet the need of packet forwarding. Generally, one token is associated with a 1-bit forwarding authority. 

If the number of tokens in the bucket is enough for forwarding the packets, the traffic conforms to the 

specification and is called conforming traffic; otherwise, the traffic does not conform to the specification 

and is called excess traffic.  

A token bucket has the following configurable parameters: 

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Mean rate: At which tokens are put into the bucket, namely, the permitted average rate of traffic. It 

is usually set to the committed information rate (CIR). 

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Burst size: the capacity of the token bucket, namely, the maximum traffic size that is permitted in 

each burst. It is usually set to the committed burst size (CBS). The set burst size must be greater 

than the maximum packet size.