Overview Of Traffic Policing And Traffic Shaping; Traffic Policing - Huawei Quidway S7700 Configuration Manual - Qos

Quidway S7700 Smart Routing Switch
Configuration Guide - QoS

2.1 Overview of Traffic Policing and Traffic Shaping

This section describes the basic concepts of traffic policing and traffic shaping and the
differences between traffic policing and traffic shaping.

2.1.1 Traffic Policing

To make full use of limited network resources, perform traffic policing for special service flows
to adapt to the allocated network resources.
Traffic policing is a traffic control action used to limit the volume of traffic and the resources
used by the traffic by monitoring the rate of the traffic.
Traffic policing controls traffic matching traffic classification rules and discards the excess
traffic, limiting traffic within a proper range and protecting network resources and carriers'
interests.
Traffic policing is widely used to limit the volume of traffic entering Internet Service Provider
(ISP) networks.
Token Bucket and Traffic Measurement
When the traffic exceeds the rate limit, the S7700 uses traffic control policies. Generally, a token
bucket is used to measure the volume of traffic.
A token bucket is considered as a container that stores a certain number of tokens. The S7700
puts tokens at the configured rate (one token bucket can forward one bit of data) in a token
bucket. When the token bucket is full, the excess tokens overflow and the number of tokens no
longer increases.
When measuring the traffic in a token bucket, the S7700 forwards packets based on the number
of tokens in the token bucket. If there are sufficient tokens in the token bucket to forward packets,
the traffic rate is within the rate limit. Otherwise, the traffic rate exceeds the rate limit.
Figure 2-1 Using a token bucket to measure the traffic
Packets that need to be
Issue 01 (2011-07-15)
sent from this interface
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2 Traffic Policing and Traffic Shaping Configuration
Put tokens into the bucket at
the set rate
Token
bucket
Drop
Continue to send
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