Overview Of Traffic Policing And Traffic Shaping; Traffic Policing; Figure 2-1 Using A Token Bucket To Measure The Traffic - Huawei Quidway S9300 Configuration Manual

2 Traffic Policing and Traffic Shaping Configuration

2.1 Overview of Traffic Policing and Traffic Shaping

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

2.1.1 Traffic Policing

2.1.2 Traffic Shaping
2.1.1 Traffic Policing
Traffic policing is a traffic control action used to limit traffic and resources by monitoring the
specification of the traffic.
Traffic policing is used to police the volume of certain traffic entering a network and retain it in
a proper range. In addition, it "punishes" the excessive traffic to protect network resources and
profits of carriers.
Traffic policing is widely used to police the volume of traffic entering the Internet Service
Provider (ISP).
Token Bucket and Traffic Measurement
When the traffic exceeds the specification, the S9300 uses traffic control policies. Generally, a
token bucket is used to measure the specification of traffic.
A token bucket is considered as a container that stores tokens of a certain number. The S9300
puts tokens at the set rate (one token bucket = 1 bit) in a token bucket. When the token bucket
is full, the excessive tokens overflows and the number of the tokens no longer increases.
When measuring the traffic in a token bucket, the S9300 forwards packets considering whether
the number of tokens in the token bucket meets the requirements for forwarding packets. If there
are sufficient tokens in the token bucket to forward packets, the traffic complies with the allowed
value; otherwise, the traffic does not comply with the allowed value or exceeds the allowed
value.

Figure 2-1 Using a token bucket to measure the traffic

Packets that need to be
2-2
sent from this interface
Classification
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Quidway S9300 Terabit Routing Switch
Put tokens into the bucket at
the set rate
Token
bucket
Drop
Configuration Guide - QoS
Continue to send
Issue 03 (2009-08-20)