Hi Reza,

Your answer doesn't help me. I know well that I can assign packets according the DSCP or CoS to queues and threshold. I need solution how to do the WTD of this queue according the CoS value.

The solution should look something like this:

mls qos srr-queue output cos-map queue 2 threshold 1 5
mls qos srr-queue output cos-map queue 2 threshold 2 3
mls qos queue-set output 1 threshold 2 75 100 100 100

and than applied on interface:

queue-set 1

I need somebody to prove this solution.

I did load this on a 3750-E but it does not seem to work.

may be I am missing someting

here is the config:

mls qos srr-queue output cos-map queue 2 threshold 1 5
mls qos srr-queue output cos-map queue 2 threshold 2 3
mls qos queue-set output 2 threshold 2 75 100 100 100
mls qos 

!
interface TenGigabitEthernet1/0/1
switchport trunk encapsulation dot1q
switchport trunk native vlan 899
switchport trunk allowed vlan 100,101
switchport mode trunk
queue-set 2
end

Here is the show command;

Switch-B(config-if)#do sh mls qos queue-set 2
Queueset: 2
Queue     :       1       2       3       4
----------------------------------------------
buffers   :      25      25      25      25
threshold1:     100      75     100     100
threshold2:     100     100     100     100
reserved  :      50     100      50      50
maximum   :     400     100     400     400
Switch-B(config-if)#

Switch-B(config-if)#do sh mls qos queue-set 1
Queueset: 1
Queue     :       1       2       3       4
----------------------------------------------
buffers   :      25      25      25      25
threshold1:     100      75     100     100
threshold2:     100     100     100     100
reserved  :      50     100      50      50
maximum   :     400     100     400     400
Switch-B(config-if)#