Hello! I've installed the 3CxPhone on my iPhone3GS and configured it for Gizmo5 & SIP2SIP. But I couldn't register at all. message: "Not Registered" My settings are as follows: Gizmo5 User = Gizmo5 user ID 17471115555(replacing with my 1747) Password = my Gizmo5 password Internal Server = blank External Server = proxy01.sipphone.com Stun Server = stun01.sipphone.com SIP2SIP User = SIP2SIP user ID 2233425555(replacing with my 2233) Password = my SIP2SIP password Internal Server = blank External Server = sip2sip.info Stun Server = proxy.sipthor.net Any suggestions to solve this problem? Thank you for your support in advance.