Traffic Shaping - H3C S5120-EI Series Configuration Manual

Traffic policing is widely used in policing traffic entering the networks of internet service providers
(ISPs). It can classify the policed traffic and take pre-defined policing actions on each packet
depending on the evaluation result:
Forwarding the traffic if the evaluation result is "conforming."
Dropping the traffic if the evaluation result is "excess."
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
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 5-2 Schematic diagram for GTS
Packets to be sent
through this interface
For example, in
packets from Switch A and drops packets exceeding the limit.
Figure 5-3 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
Tokens are put into the
bucket at the set rate
Packet
classification
Token
bucket
Figure 5-3, Switch A sends packets to Switch B. Switch B performs traffic policing on
Figure 5-2. When there are enough tokens in the
Packets sent
Queue
Packets dropped
5-3