I am pulling my hair out here. I just did a clean install of 3CX on XP SP3 (fully patched, firewall turned off, IP of 172.24.32.160) and pulled a brand new SPA502G out of the box. I gave the phone a static address of 172.24.32.161 and set the provisioning rule to http://172.24.32.160:5481/provisioning/$MA.xml. It won't pull the config. If I set the proxy and auth id/password manually it registers fine. I have also tried the actual path to the xml file (http://172.24.32.160:5481/provisioning/0018B9FFE499.xml) instead of using the variable and it still doesn't work. I have an Aastra 480i doing the same thing, but I would just like to concentrate on the Cisco for now. Below are screenshots of the phones config, the extension config, and the auto generated xml file for the phone. What am I doing wrong?