I am implementing QOS on a MPLS network, the MPLS backbone are formed by Cisco 12000 series routers.
The interlink speed between the 12000 series routers is 1 x GigabitEthernet fiber link.
My objective is to ensure voice traffic across the MPLS traffic is given priority over the other data traffic.
I have read up on the configuration examples below :-
Weighted Random Early Detection on the Cisco 12000 Series Router
http://www.cisco.com/univercd/cc/td/doc/product/software/ios112/ios112p/gsr/wred_gs.htm
The cos-queue-group command to define any WRED parameters:
random-detect-label <label> <minimum-threshold> <maximum-threshold> <mark-probability denominator>
In the example, they use different minimum and maximum threshold values for random-detect-label 0, 1, etc.
precedence 0 random-detect-label 0
precedence 1 random-detect-label 1
precedence 2 random-detect-label 2
precedence 3 random-detect-label 3
precedence 4 random-detect-label 4
precedence 5 random-detect-label 5
precedence 6 random-detect-label 6
precedence 7 random-detect-label 6
random-detect-label 0 110 367 1
random-detect-label 1 150 500 2
random-detect-label 2 250 600 3
random-detect-label 3 350 700 4
random-detect-label 4 450 800 5
random-detect-label 5 550 900 6
random-detect-label 6 650 1000 7
exponential-weighting-constant 9
From the url mentioned, the minimum and maximum threshold values were calculated based on B value,
where B = Bandwidth/(8bits/byte)/1500(bytes/packet)
I managed to derive the values for random-detect-label 0 - 110, 367
But how do we calculate the values for random-detect-label 1, 2 and so on ? How do they derive the values 150, 500, and so on ?
According to the above url, the mark-probability-denominator should be set to 1, why is it different
mark probability values were selected for the various precedence values. Any advice ?
