[cisco-voip] QoS on Catalyst 3550

[Norton, Mike]

Michael -

"We can't count on the handset marking its traffic as DSCP 46 (or CoS 5) as we're using a mash-up of Cisco IP phones, Nortel phones, etc."

Have you actually verified that, or are you just assuming it? Even the crappy $90 Grandstream SIP phone I play with Asterisk with at home will tag its packets. You are better off properly configuring your phones to mark their packets than over-complicating things at the switch. As another poster mentioned, re-marking ALL traffic from a particular subnet as DSCP EF is not particularly wise because not all traffic will be worthy of priority. For example, if your phones all fetch a new firmware image over TFTP you do not want all that going through priority queue. Only RTP stream should be EF.

-- 
Mike Norton
I.T. Support
Peace Wapiti School Division No. 76
Helpdesk: 780-831-3080
Direct: 780-831-3076



-----Original Message-----
From: cisco-voip-bounces at puck.nether.net [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Michael Crilly
Sent: Wednesday, February 02, 2011 10:14 AM
To: cisco-voip at puck.nether.net; cisco-nsp at puck.nether.net
Subject: [cisco-voip] QoS on Catalyst 3550

Greetings,

I am attempting to configure QoS on a series of 3550s, a 3560 and our core switch, a 4500. Currently, I am testing QoS configurations on the 3550, but with limited success.

Using auto qos would be nice, but we can't count on the handset marking its traffic as DSCP 46 (or CoS 5) as we're using a mash-up of Cisco IP phones, Nortel phones, etc. Therefore, we want to match traffic on our VoIP IP network, which is currently configured to run on 10.200.0.0/16.

The issue I am having is nothing is being matched when I look at the output of 'show policy-map interface fa0/3' (fa0/3, for example), but I can see packets being classified as DSCP 46 when I look at the 'mls qos interface fa0/3 stats' command.

I have attached my switch's configuration (with passwords censored). 
Could someone take a quick peak and let me know if they can see anything that is missing? It could be something obvious that my now stale eyes are missing, so a fresh pair might help.

Thanks in advance for all assistance/responses.

Kind regards,

-- 

Michael Crilly
ICT Systems Administrator
Comtek Network Systems

E: michael.crilly at comtek.co.uk