2.1.2 Traffic Shaping
Traffic shaping controls the rate of packets so that packets are sent at an even rate. It adapts the
transmission rate of packets to the downstream devices to prevent unnecessary packet loss and
congestion.
Traffic shaping also limits traffic and resources by monitoring the traffic rate. In traffic shaping,
the S3700 also uses token buckets to measure the traffic.
Difference Between Traffic Shaping and Traffic Policing
The main difference between traffic shaping and traffic policing is that the S3700 caches the
packets discarded in traffic policing. These packets are stored in a buffer or a queue, as shown
in
. When there are sufficient tokens in a token bucket, those cached packets are sent
out at an average rate.
Figure 2-2
Networking diagram of traffic shaping
Packets that need to be
sent from this interface
Continue to send
Token
bucket
Put tokens into the bucket at
the set rate
Classification
Drop
Queue
The delay may be increased just because the traffic shaping technology puts the packets into a
buffer or a queue. The traffic policing technology, however, does not cause a delay.
Traffic Shaping Features Supported by the S3700
The S3700 supports the following traffic shaping features:
l
Traffic shaping on an interface
The S3700 performs traffic shaping for all the packets that pass through an interface.
l
Traffic shaping in an interface queue
The S3700 performs traffic shaping for the packets of a certain type that pass through an
interface based on simple traffic classification. In this manner, traffic shaping based on
voice, data, and video services is implemented.
S3700HI Ethernet Switches
Configuration Guide - QoS
2 Traffic Policing and Traffic Shaping Configuration
Issue 01 (2012-03-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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