3com WX3000 Manuel D’Utilisation

 

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Figure 1-6 Diagram for traffic shaping 

Token bucket

Drop

Packet 

classification

Packets to be sent 

through this port

Continue to send

Put tokens in the bucket at the set rate

Queue

 

 

For example, if the device A sends packets to the device B. The device B will perform traffic policing on 

packets from the device A to drop the packets beyond the specification. 

In order to avoid meaningless packet loss, you can perform traffic shaping on the packets on the egress 

of the device A and cache the packets beyond the traffic policing specification in the device A. When the 

next packets can be sent, the packets cached in the buffer queues will be taken out and sent. In this way, 

all the packets sent to the device B conforms to the traffic specification of the device B. 

Traffic redirecting identifies traffic using ACLs and redirects the matched packets to specific ports. By 

traffic redirecting, you can change the way in which a packet is forwarded to achieve specific purposes. 

VLAN mapping identifies traffics using ACLs and maps the VLAN tags carrier in matched packets to 

specific VLAN tags. By employing VLAN mapping on a device connecting user networks to the carrier 

network, you can map the VLAN tags of specific user network packets to those of specific VLANs in the 

carrier network, thus meeting the requirements of the carrier network. 

When the network is congested, the problem that many packets compete for resources must be solved, 

usually through queue scheduling. 

In the following section, strict priority (SP) queues, weighted round robin (WRR),and SDWRR (Shaped 

Deficit WRR) queues are introduced.