Allied Telesis AT-GS950/48PS, AT-S111 Egress Queue vs Packet Priority Mapping

AT-GS950/48PS Switch Web Interface User’s Guide
177
Egress Queue vs
Packet Priority
Mapping
Each port has four egress queues, labeled Q0, Q1, Q2, and Q3. Q0 is the
lowest priority queue and Q3 is the highest. A packet in a high priority
egress queue is typically transmitted sooner than a packet in a low priority
queue.Table 3 lists the default mappings between the eight CoS priority
levels and the four egress queues of a switch port.
You can change these mappings. For example, you might decide that
packets with a priority of 6 and 7 need to be handled by egress queue Q3
and packets with a priority of 2 and 3 should be handled in Q1. The result
is shown in Table 4.
Table 3. Default Mappings Priority Levels to Priority Queues
IEEE 802.1p
Priority Level
Port Priority
Queue
0Q0
1Q0
2Q0
3Q0
4Q0
5Q0
6Q0
7Q0
Table 4. Customized Mappings Priority Levels to Priority Queues
IEEE 802.1p
Priority Level
Port Priority
Queue
0Q0
1Q0
2Q1
3Q1
4Q2
5Q2
6Q3
7Q3