Hello, I'm encountered a problem with Registration of Sip Trunk with a provider in Greece called OTE. i configured the 3cx server successfully and i'm able to ping their networks. The only issue i have is that the registration on the provider is invalid. Provider report me after trace log that they take invitation without domain. for example the sip server in OTE sip provider in Greece is ims.otenet.gr. and they gave me a username firstname.lastname@example.org as register server i have: ims.otenet.gr as outbound proxy i have ims.otenet.gr username +30123456 Provider inform me that take invitation from 3cx without the ims.otenet.gr in the username. Could you please help me?