D-Link DGS-3700 Series User Manual page 143

DGS-3700-12/DGS-3700-12G Series Layer 2 Gigabit Ethernet Switch User Manual
For strict priority-based scheduling, any packets residing in the higher priority queues are transmitted first. Multiple
strict priority queues empty based on their priority tags. 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 8 CoS queues, A~H, with their respective weight value: 8~1. When each queue has 10
outbound packets, they 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,
A9, B8, C7, D6, E5, F4, G3, H2,
A10, B9, C8, D7, E6, F5, G4
B10, C9, D8, E7, F6,
C10, D9, E8,
D10,
E9, F7, G5, H3,
E10, F8, G6,
F9,
F10, G7, H4,
G8,
G9, H5,
G10, H6 ~ H10
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 have been given a nonzero value,
and depending upon the weight, will follow a common weighted round-robin scheme.
Remember that the DGS-3700 Series has eight priority queues (and eight Classes of Service) for each port on the
Switch.
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