,-+-. ,----+----. ,-----+-----. |RUE| |Default | |Dial-Around| | | |Provider | | Provider | `-+-' `----+----' `-----+-----' | | | | [1] INVITE | | |-------------->| [2] INVITE | | |-------------->| Message Details: [1] INVITE Rue -> Default Provider INVITE sip:+15551234567@green.example.net;user=phone SIP/2.0 To: From: "Bob Smith" [2] INVITE Default Provider -> Dial-Around Provider INVITE sip:+15551234567@green.example.net;user=phone SIP/2.0 To: From: "Bob Smith" sip:+15552220001@red.example.net;user=phone P-Asserted-Identity: sip:+15552220001@red.example.net