PLANET FGSW-2840 - Manual (Page 161)

User’s Manual of FGSW-2840 / FGSW-4840S
161
Figure 4-7-4: SP-Mode
2. 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 and every queue can be assured of a certain service time. The weight value indicates the occupied
proportion of the resource. WRR queue overcomes the disadvantage of SP queue that the packets in the queues with
lower priority can not get service for a long time. In WRR mode, though the queues are scheduled in order, the service time
for each queue is not fixed, that is to say, if a queue is empty, the next queue will be scheduled. In this way, the bandwidth
resources are made full use of. The default weight value ratio of TC0, TC1, TC2 and TC3 is 1:2:4:8.
Figure 4-7-5: WRR-Mode
3. SP+WRR-Mode: Strict-Priority + Weight Round Robin Mode. In this mode, this Managed 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 Managed 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.
4. Equ-Mode: Equal-Mode. In this mode, all the queues occupy the bandwidth equally. The weight value ratio of all the
queues is 1:1:1:1.