This maybe the wrong forum, but I couldn't find a better one. Can somebody help me configure a Cisco 7940? I read http://www.3cx.com/sip-phones/cisco-7940g-7960g/ and followed the instructions but I'm not very experienced with this stuff at all. I've installed TFTPD64 and I think I configured it correctly, but evidently I didn't as it doesn't work. In the global settings page of TFTP I've ticked TFTP Server and Client and syslog. In the TFTP tab I have TFTP Security set to Standard and in the advanced section I have Option negotiation, show progress bar, translate unix file names and Bind TFTP to this address all ticked. In the IP drop down list I have a 127 IP and the IP of my server 192.168.1.70. I've selected the server IP. This is the machine that 3CX and TFTP are running on. I browsed to the directory in the guide C:\ProgramData\3CX\Data\Http\Interface\provisioning\fx7g4vibgb (I presume the last folder is the variable in the guide). The guide then says to set the extension up, and I've entered the mac address for extension 5002. The phone is plugged into the network switch and I can see the mac address appearing on the list of devices in the network page of the router. However, when I reboot the phone it goes through the process of starting up, but never gets a config and eventually displays "Protocol Application Invalid". I'm not sure if this is what should happen, but when I close the TFTP app and re-open it again, the IP address in the server interfaces is always the 127 IP. I know 3cx is working as I can call the external number and receive calls on the softphone. Any help would be really appreciated.