METHODS AND APPARATUS FOR USE IN ESTABLISHING SESSION INITIATION PROTOCOL COMMUNICATIONS FOR VIRTUAL PRIVATE NETWORKING

摘要

A communications application, such as a VoIP telephony application, for amobile communications device, which involves communication in accordance witha session initiation protocol (SIP). One or more processors receive a publicIP address assigned to the mobile communication device in a public network;cause a request for a virtual private network (VPN) connection with a privatenetwork to be communicated through the wireless transceiver; and refrain fromregistering with a SIP server for the communications using the public IPaddress. If the VPN connection is established, they receive a private IPaddress assigned to the mobile communication device for the VPN connection andcause a request for session registration using the private IP address to becommunicated to a SIP server of the private network. If the VPN connection andthe private IP address are not obtained within a specified period of time, thesession registration is performed using the public IP address. Communicationsare then performed in accordance with the SIP.