Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

VoIP QoS for network with 4908G-L3, 3548Xl and 2900XL

I have a star network, GBIC connections from 4908G-XL to 3 stacks with 3548XL and 2900XL's. Each stack has around 150 users with a Class-C and VLAN. I need to implement qos for VoIP. should be no problem on the 3548 and 2900's they support 802.1p, however I believe the 4908 does not. I think it only supports "IP precedence". How do I implement end-to-end QOS? Also I would like to run redundant GBIC connections between the 3548's in each closet. Do I have to change to a Class-B addressing and put all closets in the same subnet? Can I still have multiple VLAN's? thanks for help.

3 REPLIES
New Member

Re: VoIP QoS for network with 4908G-L3, 3548Xl and 2900XL

I guess you can not have end to end QoS in this case, as the CoS values will be lost when routed to 4908 L3 switch.

You may need a Cat6K in the place of 4908 if you need end to end QoS. Anyone disagrees with this thought?

http://www.cisco.com/en/US/products/hw/switches/ps606/products_qanda_item09186a00800a8922.shtml#Q21

New Member

Re: VoIP QoS for network with 4908G-L3, 3548Xl and 2900XL

I think L2 COS values will be preserved as long as the frame does not change VLAN's while routed through the 4908. I am planning to put all the IP phones on a single VLAN, and PC's on different VLAN's. This way I will have L2 COS in the 2900 switches. But no QOS on the 4908. It shouldn't be a problem since these are GIG connections, and I don't have that much data trafic to oversubscribe the GIG links.

any comments?

New Member

Re: VoIP QoS for network with 4908G-L3, 3548Xl and 2900XL

This should work absolutely fine. I agree with you hunderd percent.

As long as the packets donot get routed, the COS will be preserved. So this must work.

120
Views
0
Helpful
3
Replies