Hi! Here in spain we have a Big problem. there is a voip provider tha is fully functioning with asterisk but its imposible to do it in 3CX. "ya.com" is and ISP like telefonica for example, that offers DSL and phone voip calls. They have a router which is configurated to make voip calls.I can only get parameters from "ya.com" technical support. Here is the asterisk configuration: [general] register => +349XXXXXXXX@voipd.ya.com:tupassword:9XXXXXXXX@proxy.voip.ya.com defaultexpirey=300 [yacom] type=peer secret=tu password de VoIP username=9XXXXXXXX fromuser=+349XXXXXXXX fromdomain=voipd.ya.com realm=voipd.ya.com host=voipd.ya.com outboundproxy=proxy.voip.ya.com canrenvite=no insecure=very qualify=yes nat=no context=default This configutarion is ok for asterisk but not working on 3CX. Here is the error in 3CX: 08:02:22.605 [CM504007]: Next attempt to register 10002@Ya.com is scheduled in 5 minute 08:02:22.605 [CM504005]: Registration failed for: 10002@Ya.com; Cause: 404 NO ENCONTRADO; from IP:188.8.131.52:5060 08:02:22.121 [CM504003]: Sent registration request for 10002@Ya.com. And here is the screens configuration in 3CX. Please, I have no answers and i have been trying thos for two weeks. Need Help!! Why its posible that asterisk and 3CX dont support the same configuration? doesnt useboth SIP as a standard protocol? thanks a lot and sorry for my english.