The present invention relates to a communication method integrating network and extension forwarding to automatically broadcast caller messages to specific computer IP addresses, which will transmit in real-time the caller messages to a computer specified by each extension user, and display all kinds of information in a multimedia form, via network. The present invention comprises a main server, a caller ID module, a DTMF (Dual Tone Multi-Frequency) module, a telephone extension data base, a caller information database, a network communication interface, and a client-side program. When a user dials into an enterprise switch, the extension number that the caller intends to forward, and the caller's phone number will be retrieved, and be automatically transmitted to a computer specified by the extension user, thereby facilitating the retrieval of caller information for the extension user.