Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

Videoconferencing and CAT4000

I am new to QoS, have read quite a lot od documents but not sure how to implement it properly. I have a setup where Polycom video terminals for video conferencing are connecting to a Catalyst 4000 switch with a Sup1 engine (Layer2 support only). I have upgraded the CAT OS to the latest version. The Polycom units can mark packets with an IP precedence value. I have enabled QoS on the switch. Is there a way I can tell the switch to trust the Polycom marking. Do I need to map COS to IP PREC? I don't see a command on the switch with the SUP1 engine to do this. Is there anything else I would need for QoS on this switch? This traffic would be forwarded to CAT6000 with a SUP2 engine but I can't connect the Polycom to the 6509 because of distance limitations. If the packets are marked with a COS value on the 4000 switch would a cos to ip prec mapping be all that is needed on the 6000. Any suggestions?


Re: Videoconferencing and CAT4000

I guess, some more of these documents can help you configure QoS on a Cat4K. I am not very sure of the CoS to IP Precedence mapping. May be you can checkout the same in the following documents.

Quality of Service on Catalyst 4000 Running CatOS Frequently Asked Questions

Configuring QoS

New Member

Re: Videoconferencing and CAT4000

I am not familar with the Sup I for the Cat 4 but I would think if it did not support QOS it would still foward this. I suggest you put a sniffer on the other side of the Cat 4 and see what it shows on the TOS byte.

CreatePlease to create content