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

VLAN for IP phone


we are in the process of rolling out an IP phone system in a three warehouse office environment.

The basic setup per building is 2 x 3524 inline power switches linked by a gigastack card.

There is then another gbic card which connects to a fiber backbone to join the pairs of switches in each building to the other buildings.

Many of the design guides I have read from cisco seem to deal with a single switches geographically seperate office.

I am trying to determine the best way to configure VLANs in the given situation, with the intent being on keeping the phones and phone servers isolated from the PC's and Network Servers. Due to the primary WAN routers being owned by the carrier, a second router is on site for routing only voice data across the WAN. So this router can be kept seperate from the PC's, etc.

Is there any specific documentation or methodology to follow in this situation?

Additionally, the DHCP server will service both PC's and Phones and thus need access to both VLANs. But if we run trunks on all the switches then I believe it is not possible to create a multi VLAN member port...

Any advice or documents dealing with covering a similar situation would be greatly appreciated.

Thanks in advance

Community Member

Re: VLAN for IP phone

You could set up a seperate VLAN for your phones the way cisco define it is as a AuxVlan. You configure your switch with it's normal Data VLAN and also configure an auxVlan on the same port. I would use a seperate address space too, and set up a new scope on your DHCP server with a helper address on the router to allow your phones to broadcast for an address. alternativly you could install the DHCP server serivice on one of your CM's.

The AVVID design guide is a very good document and can be found on CCO.

Hope this helps

Community Member

Re: VLAN for IP phone

You may want to check whether the carriers router is optimised for voice. Of course it depends on the speed of your WAN links but if you are using links less than 2MB you may want to talk to them about implementing priority mechanisms for voice traffic. Otherwise you might get a bottle neck. Really depends on what you are doing.

作成コンテンツを作成するには してください