QoS Policy-Map for IP Phones, Cisco VTAs, and Tandberg Endpoints

[dtran]

Hello all,

I am running a Cisco IPTel environment with CCM 4.1.3 and about 1300+ Cisco IP Phones, 50+ Cisco VTA devices and 20+ Tandberg endpoints, both voice and video devices are on the same network. Currently I am matching voice and video traffics by IP address and mark them as IP precedence 5. I am looking into changing my QoS policy-map to tag video traffic as IP precedence 4 and I think the only way for me accomplish this is to match voice and video traffics by port instead of IP address.

I appreciate any advices/suggestions !!! A sample config of a Policy-map would be a great help !!!

Thanks so much in advance !!!

Danny

[Nicholas Matthews]

Hi Danny,

Two fundamental ways to match this:

class-map video1

match ip dscp af41

class-map video2

match protocol rtp video

video1 assumes you have consistent DSCP markings for your video endpoints. This is done by default on Cisco endpoints. You would need to confirm with the other video endpoints, and also make sure that your switches aren't going to remark this traffic is something else.

video2 uses NBAR which will inspect the RTP packet to see if it is video or not, which may work better for your scenario.

I would test both to see how it works for your network.

-nick

[dtran]

Hello Nick !!! Thanks for helping me out !!

I am using "auto QoS" on the switches (3750 and 6509 switches). Do you see any concerns with that ?

would it be easier if I match by port number verses DSCP value ?

Thanks again !!

Danny

[Nicholas Matthews]

Hi Danny,

If you're using auto qos you would want to check whether or not you're trusting DSCP or COS.

If you're trusting COS you want to see which DSCP value you're mapping COS 4 to. If it's AF41 you should be fine.

Otherwise, you're better off trusting DSCP.

hth,

nick