I am in the situation of making Cisco CallManager 4.1(3) and 7961 phones work on a 3Com 7757 switch. The network is designed with a Cisco 6509 as the Core switch, and four 7757s connected to it for users. I am able to get the phones to work on the 3Com, but I can't get DHCP option 184 working properly on my MS Windows 2003 DHCP Server. As a result, the phone never gets tagged to the voice VLAN and never gets the IP address from the scope I have identified for voice, it only gets an address from the scope for the data network. Anyone out there have any experience in this area? Yes, I know it would have been easier to stay all Cisco, but this was done before I got here. Thanks in advance.