Dell 53-1002116-01 manual Configuring the QoS trust mode, Incoming CoS User Priority

Queueing 10

Table 16 presents the Layer 2 QoS untrusted user priority generation table.

TABLE 16	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)

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.

Table 17 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.

TABLE 17	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

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.

Dell Converged Enhanced Ethernet Administrator’s Guide	95
53-1002116-01