VoIP QoS on Catalyst 6500

[scjlin]

Hi, I am new to VoIP and I haven’t done much of QoS configuration except bandwidth limitation.

Currently we are using Avaya as our VoIP (not a 100% over IP, I mean the phone does not connect to switch port, it hookup to Avaya PBX blade and it connect to catalyst switch.)

The catalyst 6509 had SUP1A with different vlans, there is a voice vlan for routing the voice from pbx blade to voice servers. In catalyst 6509 there is a trunk port configured and connect to laser and to the next building’s catalyst 3550 to serve voice and data.
Shows: (Catalyst 6509 (trunk) --- Laser === Laser -– Catalyst 3550 (trunk)).
Now my problem is I need to configure QoS on these two trunk ports (catalyst 6509 and catalyst 3550). I wonder if any one has any suggestion on the configuration that can help me?? Thanks in advanced,

SL

 

[nichev]

IP telephony or VoIP's packets are pre-marked, this means you don't have to mark them and make some special QoS, the only thing you have to do is to let the Cats do the job for you:

s-sof-0103(config-if)#mls qos trust ?
cos Classify by packet COS
device trusted device class
dscp Classify by packet DSCP
ip-precedence Classify by packet IP precedence

s-sof-0103(config-if)#mls qos trust cos

That's it

Hope this helps.