H3C S5120-EI Series, Руководство по эксплуатации

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Forwarding the traffic if the evaluation result is “conforming.”
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Dropping the traffic if the evaluation result is “excess.”
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Marking a conforming packet or a non-conforming packet with a new DSCP precedence value and
forwarding the packet.
Traffic Shaping
Traffic shaping provides measures to adjust the rate of outbound traffic actively. A typical traffic shaping
application is to limit the local traffic output rate according to the downstream traffic policing parameters.
The difference between traffic policing and GTS is that packets to be dropped in traffic policing are
cached in a buffer or queue in GTS, as shown in
Figure 4-2 . When there are enough tokens in the token
bucket, these cached packets are sent at an even rate. Traffic shaping may result in an additional delay
while traffic policing does not.
Figure 4-2
Schematic diagram for GTS
Token
bucket
Packets dropped
Packet
classification
Packets to be sent
through this interface
Packets sent
Tokens are put into the
bucket at the set rate
Queue
For example, in
Figure 4-3 , Switch A sends packets to Switch B. Switch B performs traffic policing on
packets from Switch A and drops packets exceeding the limit.
Figure 4-3
GTS application
You can perform traffic shaping for the packets on the outgoing interface of Switch A to avoid
unnecessary packet loss. Packets exceeding the limit are cached in Switch A. Once resources are
released, traffic shaping takes out the cached packets and sends them out. In this way, all the traffic
sent to Switch B conforms to the traffic specification defined in Switch B.