D-Link DGS-3224TGR - Switch User Manual - Qos Output Scheduling

DGS-3224TGR Gigabit Ethernet Switch User’s Guide 

70 

Q4 is assigned to the switch’s Q4 queue. 

Q5 is assigned to the switch’s Q5 queue. 

Q6 is assigned to the switch’s Q6 queue. 

Q7 is assigned to the switch’s Q7 queue.

For strict priority-based scheduling, any packets residing in the higher priority queues are transmitted first. Only when these 

queues are empty, are packets of lower priority transmitted.   

For weighted round-robin queuing, the number of packets sent from each priority queue depends upon the assigned weight. 

For a configuration of eight CoS queues, A~H with their respective weight value: 8~1, the packets are sent in the following 

sequence: A1, B1, C1, D1, E1, F1, G1, H1, A2, B2, C2, D2, E2, F2, G2, A3, B3, C3, D3, E3, F3, A4, B4, C4, D4, E4, A5, 

B5, C5, D5, A6, B6, C6, A7, B7, A8, A1, B1, C1, D1, E1, F1, G1, H1. 

For weighted round-robin queuing, if each CoS queue has the same weight value, then each CoS queue has an equal 

opportunity to send packets just like round-robin queuing. 

For weighted round-robin queuing, if the weight for a CoS is set to 0, then it will continue processing the packets from this 

CoS until there are no more packets for this CoS. The other CoS queues that has been given a nonzero value, and depending 

upon the weight, they will follow a common weighted round-robin scheme. 

Remember that the DGS-3224TGR has eight priority queues (and thus eight Classes of Service) for each port on the switch. 

QOS Output Scheduling 

Figure 6- 53.  QOS Output Scheduling window