H3C Technologies H3C S6300 Series Switches - Manual (Page 54)

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Figure 14 WRR queuing
Assume a port provides eight output queues. WRR assigns each queue a weight value (represented by
w7, w6, w5, w4, w3, w2, w1, or w0) to decide the proportion of resources assigned to the queue.
The switch implements the weight of a queue by scheduling a certain number of bytes (byte-count WRR)
or packets (packet-based WRR) for that queue. Take byte-count WRR as an example: On a 10-Gbps port,
you can configure the weight values of WRR queuing to 5, 5, 3, 3, 1, 1, 1, and 1 (corresponding to w7,
w6, w5, w4, w3, w2, w1, and w0, respectively). In this way, the queue with the lowest priority can get
a minimum of 500 Mbps of bandwidth. WRR solves the problem that SP queuing might fail to serve
packets in low-priority queues for a long time.
The switch supports WRR priority queue groups. You can assign the output queues to WRR priority queue
group 1 and WRR priority queue group 2. You can configure the weight for each queue and WRR
schedules queues in each group based on the weights in a round robin manner. WRR schedules the
traffic of group 1 and the traffic of group 2 in the ratio of 1:1.
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