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H3C Technologies H3C S6300 Series Switches User Manual

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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