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New Member

VLANs and VoIP on the same port

Hello, we want to move our VoIP system on its own vlan. We currently have everything on one big broadcast domain. I have been doing some reading and have head about Voice Vlans and switchport modes. All of our computers are connected to our ip phones so they are on the same physical line. The phones are Aastra 480i and they run on a sphericall phone system. The phones can tag the phone data with 802.1p/q. If im using static port based vlans how would i configure the ports to accepts these 2 diffrent vlans?

5 REPLIES

Re: VLANs and VoIP on the same port

I dont think the voice vlan concept works with other vendor phones, as the VVID is exchanged through CDP which only Cisco phones understand.

New Member

Re: VLANs and VoIP on the same port

To do this, use this command,

switchport voice vlan "vlan number"

this will make it use the native vlan 1 for pc's and use for voice vlan for phones.

Make sure you have trunking set up on your switches, and that the trunk encapsualtion is dot1q.

HTH

CARLOS

Re: VLANs and VoIP on the same port

Hi Friends,

I have tried many a times with Avaya Ip phones and Cisco swiches and it works fine.

Actually what I think CDP is used for inline power negotation so if you dont have Cisco switches you have to use external power supply. Also now a days switches are coming which internal power supply which supoprt IEEE standard so if we have those switches we can use other vendors ip phones without external power supply.

Anoher thing I will always recommend not to configure trunk especially cause tht may result in pc getting DHCP ip adress later. I have experienced many a times this situation. When you configure switchport voice vlan command on the switch it automatically forms an internal trunk which is not displayed on the switch but internally it works.

Right now I was not able to find one cisoc doc which especially says no need for trunk if you configure switchport voice vlan command on switch.

So just 2 commands

switchport voice vlan

switchport access vlan

Works perfectly fine.

HTH

Ankur

New Member

Re: VLANs and VoIP on the same port

If the phone doesn't support voice vlan the solution could be to configure a trunk on the switch. If the phone supports trunks and can send voice and data to different vlans this should work.

New Member

Re: VLANs and VoIP on the same port

Thanks alot guys for the help and the second opinion. On our currnet enviroment we are currently using a 2950 switch. In the future once we deploy the solution we will be using the Express 500g. If you guys have any links to good docs for this purpose that would be great. I have been searching for days but the subject of vlans and voip is so broad its hard to find what you are looking for.

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