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New Member

mitel 5125 ip phone setup

We are getting ready to install a mitel voip phone system on our Cisco network. We have been doing some research on how to configure our 4006 layer3 switch but have not found anything that states which config is better over another. From what we've found we should create an auxiliary vlan, set qos(doc refers as cos?) and the document offers different options for the packets (dot1, untagged, etc) Could someone offer a good suggestion which way to setup the vlan on our 4006 for the ip phones.

thank you in advance,



Re: mitel 5125 ip phone setup

I don't think an auxilary VLAN will work for a Mitel phone as it doesn't use CDP to discover what VLAN to use for voice.

I would setup the ports with phones attached as trunk ports using 802.1q encapsulation and have the qos trust cos. That is the way I always setup for Mitel IP phones back when I used to work for an employer that sold them.

feel free to ask more questions on this one, haven't had to deal with Mitel in a while!

New Member

Re: mitel 5125 ip phone setup

okay. will phones still on a different ip subnet than pc's? I won't have enough ip's otherwise. As far as CDP goes, the mitel book I was reading states that Mitel can now use CDP.

thank you


Re: mitel 5125 ip phone setup

Mitel might have updated firmware between my experience and now but the method for booting a Mitel phone on a Cisco switch went like this:

1. Phone boots to native vlan (on a trunked 802.1q port)

2. Phone receives custom options from DHCP server (one option being the VLAN for voice and another option being a string "MITEL IP PHONE")

3. Phone receives Voice VLAN information from DHCP and reboots but this time using 802.1q encapsulation with the Voice VLAN tag and then receives programming information now that it is on the Voice Vlan talking to the Mitel IP PBX.

So yes the voice equipment will still be on a seperate VLAN but Mitel has to have the phones boot into the data VLAN first to receive the DHCP info regarding what VLAN to use for voice. I really doubt they have changed this bootup procedure.

New Member

Re: mitel 5125 ip phone setup

some mitel phones do support cdp starting with 5.1. console doesn't as i remember.

so now what i did during the installation was plugging 5220 into any port configured for voice access (i.e. 4-port switch on ICP), upgrading it's firmare. after that taking correct vlan from cisco switch goes fine. much less headache with dhcp then priviously.