3.7.2 CoS and queuing priorities
CoS values are used as an index for showing the priority of frames on the Switch. The queuing priority indicates how easily a frame can be discarded for each queue.
The following table describes the specifiable range of CoS values and queuing priority values.
|
Item |
Range |
|---|---|
|
CoS value |
0~7 |
|
Queuing priority |
1~3 |
Frames without flow-control priority determination use the default CoS and queuing priority. The following tables show the defaults for CoS and queuing priorities.
|
Frame type |
Default |
|
|---|---|---|
|
CoS value |
Queuing priority |
|
|
Frame to be relayed |
User priority mapping* |
3 |
- #
-
Relay frames matching the following QoS flow-conditions do not follow the user-priority mapping, and CoS is fixed to 3.
.A marker is specified but no CoS is specified.
.A queuing priority is specified in priority determination, and a CoS is not specified.
.Bandwidth monitoring is specified but CoS is not specified.
The following frames fixedly determine CoS and queuing priorities:
The following table lists the frames that cannot be changed by priority determination.
|
Frame type |
CoS value |
Queuing priority |
|---|---|---|
|
Frames spontaneously sent by the Switch Frames forwarded by the Switch by software |
7 |
3 |
|
Mirroring frame |
0 |
3 |