Dell 53-1002116-01 manual Multicast queue scheduling, Scheduling the QoS queue

10 Scheduling

Figure 9 shows that extending the frame scheduler to a hybrid SP+WRR system is fairly straightforward. All SP queues are considered strictly higher priority than WRR so they are serviced first. Once all SP queues are drained, then the normal WRR scheduling behavior is applied to the non-empty WRR queues.

FIGURE 9 Strict priority and Weighted Round Robin scheduler

Scheduling the QoS queue

To specify the schedule to use, perform the following steps from Privileged EXEC mode. 1. Enter global configuration mode.

switch#configure terminal

2. Specify the schedule to use and the traffic class to bandwidth mapping.

switch(config)#qos queue scheduler strict-priority 4 dwrr 10 20 30 40

The following example sets the traffic class frame scheduler for 4 Strict Priority Traffic Class and 4 DWRR Traffic Class with Traffic Class 0 getting 10 percent bandwidth, Traffic Class 1 getting 20 percent bandwidth, Traffic Class 2 getting 30 percent bandwidth, and Traffic Class 3 getting 40 percent bandwidth.

switch:admin>cmsh switch>enable switch#configure terminal

Enter configuration commands, one per line. End with CNTL/Z. switch(config)#qos queue scheduler strict-priority 4 dwrr 10 20 30 40 switch(config)#end

3. Enter the copy command to save the running-config file to the startup-config file.

switch#copy running-config startup-config

Multicast queue scheduling

The multicast traffic classes are numbered from 0 to 7; higher numbered traffic classes are considered higher priority. A fixed mapping from multicast traffic class to equivalent unicast traffic class is applied to select the queue scheduling behavior. Table 21 presents the multicast traffic class equivalence mapping applied.

TABLE 21 Multicast traffic class equivalence mapping

Multicast traffic class Equivalent unicast traffic class

00

11

22

106	Dell Converged Enhanced Ethernet Administrator’s Guide
	53-1002116-01