QoS/Auto QoS Config

[codflanglers]

Firstly, forgive the cross post but I think it is better suited here..

Setting up QoS on a network and was going to use auto qos as I just need to prioritize voice traffic. Can anyone see any issue with this config? Anything else I need? Effectively, I don't need to classify or police anything I just need to trust the phone marking all the way through.

FYI the phones are not Cisco but mark their traffic as dscp 46 and use cdp. The access switches are 2960 and core is 3750.

Cisco 2960

Global Config

mls qos (should be added by auto qos)
mls qos map cos-dscp 0 8 16 26 32 46 48 56 (to rewrite the existing incorrect map)

All Ports

auto qos voip trust
mls qos trust dscp (to mark dscp rather than cos)

Cisco 3750

mls qos

mls qos map cos-dscp 0 8 16 24 32 46 48 56
mls qos srr-queue input bandwidth 90 10
mls qos srr-queue input threshold 1 8 16
mls qos srr-queue input threshold 2 34 66
mls qos srr-queue input buffers 67 33
mls qos srr-queue input cos-map queue 1 threshold 2 1
mls qos srr-queue input cos-map queue 1 threshold 3 0
mls qos srr-queue input cos-map queue 2 threshold 1 2
mls qos srr-queue input cos-map queue 2 threshold 2 4 6 7
mls qos srr-queue input cos-map queue 2 threshold 3 3 5
mls qos srr-queue input dscp-map queue 1 threshold 2 9 10 11 12 13 14 15
mls qos srr-queue input dscp-map queue 1 threshold 3 0 1 2 3 4 5 6 7
mls qos srr-queue input dscp-map queue 1 threshold 3 32
mls qos srr-queue input dscp-map queue 2 threshold 1 16 17 18 19 20 21 22 23
mls qos srr-queue input dscp-map queue 2 threshold 2 33 34 35 36 37 38 39 48
mls qos srr-queue input dscp-map queue 2 threshold 2 49 50 51 52 53 54 55 56
mls qos srr-queue input dscp-map queue 2 threshold 2 57 58 59 60 61 62 63
mls qos srr-queue input dscp-map queue 2 threshold 3 24 25 26 27 28 29 30 31
mls qos srr-queue input dscp-map queue 2 threshold 3 40 41 42 43 44 45 46 47
mls qos srr-queue output cos-map queue 1 threshold 3 5
mls qos srr-queue output cos-map queue 2 threshold 3 3 6 7
mls qos srr-queue output cos-map queue 3 threshold 3 2 4
mls qos srr-queue output cos-map queue 4 threshold 2 1
mls qos srr-queue output cos-map queue 4 threshold 3 0
mls qos srr-queue output dscp-map queue 1 threshold 3 40 41 42 43 44 45 46 47
mls qos srr-queue output dscp-map queue 2 threshold 3 24 25 26 27 28 29 30 31
mls qos srr-queue output dscp-map queue 2 threshold 3 48 49 50 51 52 53 54 55
mls qos srr-queue output dscp-map queue 2 threshold 3 56 57 58 59 60 61 62 63
mls qos srr-queue output dscp-map queue 3 threshold 3 16 17 18 19 20 21 22 23
mls qos srr-queue output dscp-map queue 3 threshold 3 32 33 34 35 36 37 38 39
mls qos srr-queue output dscp-map queue 4 threshold 1 8
mls qos srr-queue output dscp-map queue 4 threshold 2 9 10 11 12 13 14 15
mls qos srr-queue output dscp-map queue 4 threshold 3 0 1 2 3 4 5 6 7
mls qos queue-set output 1 threshold 1 138 138 92 138
mls qos queue-set output 1 threshold 2 138 138 92 400
mls qos queue-set output 1 threshold 3 36 77 100 318
mls qos queue-set output 1 threshold 4 20 50 67 400
mls qos queue-set output 2 threshold 1 149 149 100 149
mls qos queue-set output 2 threshold 2 118 118 100 235
mls qos queue-set output 2 threshold 3 41 68 100 272
mls qos queue-set output 2 threshold 4 42 72 100 242
mls qos queue-set output 1 buffers 10 10 26 54
mls qos queue-set output 2 buffers 16 6 17 61

All Ports (to be put on port channel members, not port channel interface)

mls qos trust dscp (to mark dscp rather than cos)

- See more at: https://supportforums.cisco.com/discussion/12540171/qosauto-qos#sthash.BDVZOqfr.dpuf

[Terry Cheema]

Yes the switch config looks fine. If its not a single site deployment, you will need QoS on your WAN routers to prioritize the VoIP traffic over your MPLS as well.

-Terry

Please rate all helpful posts

[Wilson Samuel]

Just adding to Terry's point. Also make sure that the switch interface where Servers are connecting, they are honoring the DSCP marking of the Packet and not the CoS marking.

HTH

[codflanglers]

OK, well I have the config in place and all is well on the switches as I can the dscp 46 traffic marked. However, when it goes over the WAN link to a switch in the DC I see no traffic being marked as dscp 46.

Now, my ISP is running a layer 2 connection between the local site and the DC over fibre so I assumed everything would be OK. I thought as dscp would be in the layer 3 header information, that this would not be touched by a layer 2 connection. Am I wrong?

The ISP does not run QoS, so what's the default operation of not running QoS; to leave dscp markings as is or to remove them completely?

If it's the latter I am going to have to get the ISP to honour at least the cos markings, which may prove time consuming.

[Terry Cheema]

Normally for most of the Catalyst switches default action when QoS is disabled should be to pass-through the marking unchanged. And since you are sending dscp markings which are hidden in the L3 or IP Packet Header, then a purely L2 switch should not be able to discard the markings technically as well.

Can you see the marking at your edge device at A end - router or switch?

-Terry