Brocade Communications Systems 53-1001761-01 Manual De Usuario

Queueing

9

 presents the Layer 2 QoS untrusted user priority generation table.

NOTE
Non-tagged Ethernet frames are interpreted as incoming CoS value of 0 (zero).

You can override the default user-priority mapping by applying explicit user-priority mappings.

When neighboring devices are trusted and able to properly set QoS then Layer 2 QoS trust can be 
set to COS and the IEEE 802.1Q default-priority mapping is applied.

 presents the Layer 2 CoS user priority generation table conforming to 802.1Q default 

mapping. You can override this default user priority table per port if you want to change (mutate) 
the COS value. 

Configuring the QoS trust mode

The QoS trust mode controls user priority mapping of incoming traffic. The Class of Service (CoS) 
mode sets the user priority based on the incoming CoS value. If the incoming packet is not priority 
tagged, then fallback is to the Interface Default CoS value. 

NOTE
When a CEE map is applied on an interface, the qos trust command is not allowed. The CEE map 
always puts the interface in the CoS trust mode. 

TABLE 15

Default priority value of untrusted interfaces

Incoming CoS

User Priority

0

port <user priority> (default 0)

1

port <user priority> (default 0)

2

port <user priority> (default 0)

3

port <user priority> (default 0)

4

port <user priority> (default 0)

5

port <user priority> (default 0)

6

port <user priority> (default 0)

7

port <user priority> (default 0)

TABLE 16

IEEE 802.1Q default priority mapping

Incoming CoS 

User Priority

0

0

1

1

2

2

3

3

4

4

5

5

6

6

7

7