H3C Technologies H3C S6300 Series Switches - Manual (Page 55)

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WFQ queuing
Figure 15 WFQ queuing
WFQ is similar to WRR. The difference is that WFQ enables you to set guaranteed bandwidth that a
WFQ queue can get during congestion.
The switch supports WFQ priority queue groups. You can assign the output queues to WFQ priority
queue group 1 and WFQ priority queue group 2. You can configure the weight for each queue and
WFQ schedules queues in each group based on the weights in a round robin manner. WFQ schedules
the traffic of group 1 and the traffic of group 2 in the ratio of 1:1.
SP+WRR queuing
You can configure some queues on an interface to use SP queuing and others to use WRR queuing by
assigning the queues to the SP group and WRR groups (group 1 and group 2). With this SP+WRR
queuing method, the system first schedules the queues in the SP group and then schedules queues in the
WRR groups when all queues in the SP group are empty. The queues in the SP group are scheduled
based on their priorities. The queues in a WRR group are scheduled based on their weights, and the two
WRR groups are scheduled in the ratio of 1:1.
SP+WFQ queuing
You can configure some queues on an interface to use SP queuing and others to use WFQ queuing by
assigning the queues to the SP group and WFQ groups (group 1 and group 2). With this SP+WFQ
queuing method, the system schedules traffic as follows:
1. The system schedules the traffic conforming to the minimum guaranteed bandwidth in each WFQ
group and schedules the traffic of the two WFQ groups in the ratio of 1:1 in a round robin manner.
2. The system uses SP to schedule queues in the SP group.
3. If there is remaining bandwidth, the system schedules the traffic of queues in each WFQ group
based on their weights and schedules the traffic of the two WFQ groups in the ratio of 1:1 ratio in
a round robin manner.
Queue 0 Weight 1
……
Queue 1 Weight 2
Queue N-2 Weight N-1
Queue N-1 Weight N
Packets to be sent through
this port
Sent packets
Interface
Queue
scheduling
Sending queue
Packet
classification