Internet telephone equipment for communications system using wide area data communications network

摘要

The telephone apparatus includes an integrated services digital network (ISDN) terminal adapter for sending a setup message via an ISDN network, to enable a connection to be made via the internet, if agreed by the called party. The apparatus includes a calling party telephone (1) and ISDN adapter (2) which is used to send a call setup message, including its input (IP) access point subaddress (8), to a called part telephone (6), via an ISDN network. The called party telephone is rung, and in response to the telephone going off-hook a connection is made to an internet access point (9). The IP address of the access point is sent back to the calling party via the ISDN network. The calling party telephone then connects to the internet (10), and the ISDN link is dropped. The call setup message allows the calling party telephone to list the preferred internet service providers (ISPs), so that the called party may choose a provider, and send details of its choice back to the calling party. This enables the call to proceed via just one ISP. If the called party does not wish, or is unable, to go onto the internet then the call may proceed via an ISDN connection.