I work as a Network Administrator for a smaller company of about 90 employee's and we use Adtran phones throughout the company. We are currently trying to upgrade our network infrastructure and in the process incorporate Vlan tagging and also utilize the PC port on the back of the phone. We are looking into handing out the phone Vlan ID and enable Vlan Tagging through the option 157 DHCP on our DHCP server. I have figured out how to get DHCP to hand out the correct Vlan ID but not enable Vlan Tagging/L2 Tagging. The next problem is we want to keep the phones on, lets say for demo purposes, Vlan 100 and computers on Vlan 200, while utilizing the PC port on the phone. Let me try to make this a little easier to understand. Computers hooked to phones, phones hooked to cisco poe 24 port switch, computers need to be on Vlan 200, phones need to be Vlan 100, and have DHCP handle Vlan ID and Tagging for phones.