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802.1Q on switch port for IP Telephony

I just finished watching a seminar on preparing your LAN for IP telephony. In it they mentioned using 2 VLANs on a port, one for data and the other for voice; using 802.1Q. What it didn't mention is if 802.1Q is supported on 10M to the desktop or if 100M to the desktop is required.

I have been told, but have not substantiated, that the NORTEL Passport 8600 does indeed support 802.1Q over 10M.

Has anyone had any experience testing this on any of the CAT switches or the Passport 8600?

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Cisco Employee

Re: 802.1Q on switch port for IP Telephony

Talking specifically about linecards that you would connects your hosts to (in this case, IP phones), you would need a 10/100 or 100 port to actually do dot1q trunking.

However, you don't have to actually run the port at 100Mbps speed. If it negotiates to 10Mbps then the trunking would still work.

But keep in mind that with our voice/data VLAN trunking, the automated way to do this is accomplished through the CDP protocol. So on the switch port you configure what you want the data and voice vlan numbers to be, and if a phone is attached and negotiates CDP, the switch will tell it how to do the trunking and the vlan tags to use.

You should be able to do this without CDP but you would have to manually program each phone with the VLAN information.

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