I have had my 3CX system working fine here at home behind a router. I took it to our church/school, and now I am in our Domain there. I can receive incoming calls, but cannot make any outbound calls at all. I have checked the 'Direct SIP' setting, which is set to the IP Address of the PBX, but still no luck. When I try to dial-out, I simply get dead air. I increased the logging on the 3CX system, and when I try to make any calls outbound, nothing gets logged. I do have an outbound rule that I kept from when I had it working here at home. I also opened the right port, which is 69 to 50000 to be safe both here and at Church/School. My configuration is the latest 3CX software with A580IP Siemens phones. Is there something specific why this phone would not work in a Domain/Networked environment vs. here at home? I saw an article link (wiki) on the 'Direct SIP' setup in the 3CX Coniguration, General Settings, Advanced, Direct SIP coniguration. Let me know if I need any MX records added to DNS, for some reason, or you have seen this issue before? Let me know. Thanks.