Note: 
To complete QoS function configuration, you have to go to the Schedule Mode page to select a 
schedule mode after the configuration is finished on this page. 
Configuration Procedure: 
Step  Operation  Description 
1 Configure the mapping 
relation between the 802.1P 
priority Tag/CoS and the TC 
Required. On QoS→DiffServ→802.1P/CoS mapping 
page, configure the mapping relation between the 
802.1P priority Tag/CoS and the TC. 
2  Select a schedule mode  Required.  On  QoS→DiffServ→Schedule Mode 
page,, select a schedule mode. 
9.1.4 Schedule Mode 
On this page you can select a schedule mode for the switch. When the network is congested, the 
problem that many packets compete for resources must be solved, usually in the way of queue 
scheduling. The switch will control the forwarding sequence of the packets according to the priority 
queues and scheduling algorithms you set. On this switch, the priority levels are labeled as TC0, 
TC1… TC3. 
Choose the menu QoS→DiffServ→Schedule Mode to load the following page. 
 
Figure 9-9 Schedule Mode 
The following entries are displayed on this screen: 
  Schedule Mode Config 
SP-Mode:  Strict-Priority Mode. In this mode, the queue with higher priority 
will occupy the whole bandwidth. Packets in the queue with lower 
priority are sent only when the queue with higher priority is empty. 
 
WRR-Mode:  Weight Round Robin Mode. In this mode, packets in all the queues 
are sent in order based on the weight value for each queue. The 
weight value ratio of TC0, TC1, TC2 and TC3 is 1:2:4:8. 
 
SP+WRR-Mode:  Strict-Priority + Weight Round Robin Mode. In this mode, this 
switch provides two scheduling groups, SP group and WRR 
group. Queues in SP group and WRR group are scheduled strictly 
based on strict-priority mode while the queues inside WRR group 
follow the WRR mode. In SP+WRR mode, TC3 is in the SP group; 
TC0, TC1 and TC2 belong to the WRR group and the weight value 
ratio of TC0, TC1 and TC2 is 1:2:4. In this way, when scheduling 
queues, the switch allows TC3 to occupy the whole bandwidth 
following the SP mode and the TC0, TC1 and TC2 in the WRR 
group will take up the bandwidth according to their ratio 1:2:4. 
 
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