Abstract: A system for dialing from Internet extension of other SIP proxy server to conventional extension is disclosed. A VoIP gateway or an IP auto attendant is used for dialing from Internet extension to conventional extension. The phone number of the Private Branch Exchange and the voice guidance are not needed. The calling number of SIP message is interpreted directly and converted into DTMF (Dual-tone multi-frequency) messages for dialing into a conventional extension.

Abstract: The present invention provides an NAT (Network Address Translator) traversal method in Session Initiation Protocol (SIP) for solving the problems of SIP in Internet phone (VoIP) under current Internet environment. In other words, the present invention solves the SIP problems caused by NAT (Network Address Translator) that P2P (Peer to Peer) transmission cannot traverse the NAT firewall directly. The major content of the present invention is that the computer conducts multiple registrations before issuing an Invite message in order to detect the rule of the NAT server to assign port number and IP address. Additional commands or parameters beyond the SIP standard are not required for the NAT traversal function. Hence, the capability of SIP for a NAT traversal function is provided without no additional commands or parameters.

Abstract: A system for dialing from Internet extension of other SIP proxy server to conventional extension is disclosed. A VoIP gateway or an IP auto attendant is used for dialing from Internet extension to conventional extension. The phone number of the Private Branch Exchange and the voice guidance are not needed. The calling number of SIP message is interpreted directly and converted into DTMF (Dual-tone multi-frequency) messages for dialing into a conventional extension.

Abstract: A system for dialing from Internet extension to conventional extension is disclosed. A VoIP gateway or an IP auto attendant is used for dialing from Internet extension to conventional extension. The phone number of the Private Branch Exchange and the voice guidance are not needed. The calling number of SIP message is interpreted directly and converted into DTMF (Dual-tone multi-frequency) messages for dialing into a conventional extension.

Abstract: A method for dialing between Internet extensions is disclosed. When dialing between Internet extensions, just dial the switchboard phone number of SIP proxy server plus “-” and then dial the extension phone number of the opposite Internet extension directly. It is not necessary to use a voice guidance for asking dialing of the extension phone number of the opposite Internet extension.

Abstract: A method for dialing from Internet extension to conventional extension is disclosed. A VoIP gateway or an IP auto attendants is used for dialing from Internet extension to conventional extension. The phone number of the Private Branch Exchange and the voice guidance are not needed. The calling number of SIP message is interpreted directly and converted into DTMF (Dual-tone multi-frequency) messages for dialing into a conventional extension.

Abstract: A method for dialing between Internet extensions is disclosed. When dialing between Internet extensions, just dial the switchboard phone number of SIP proxy server plus “-” and then dial the extension phone number of the opposite Internet extension directly. It is not necessary to use a voice guidance for asking dialing of the extension phone number of the opposite Internet extension.

Abstract: The present invention provides an NAT (Network Address Translator) traversal method in Session Initiation Protocol (SIP) for solving the problems of SIP in Internet phone (VoIP) under current Internet environment. In other words, the present invention solves the SIP problems caused by NAT (Network Address Translator) that P2P (Peer to Peer) transmission cannot traverse the NAT firewall directly.