Voice communication system and voice communication method

[54] VOICE COMMUNICATION SYSTEM AND VOICE COMMUNICATION METHOD

[75] Inventors: Naoko Iwami; Susumu Matsui, both of Machida; Keiko Takahara,

Kawasaki, all of Japan

[73] Assignee: Hitachi, Ltd., Tokyo, Japan

[21] Appl. No.: 357,189

[22] Filed: Dec. 13,1994

[30] Foreign Application Priority Data

Dec. 15, 1993 [JP] Japan 5-343162

[51] Int. CI.6 H04L 12/56

[52] U.S. CI 370/352

[58] Field of Search 370/60, 60.1, 94.1,

370/94.2, 110.1, 85.13; 379/94, 95, 96

[56] References Cited

U.S. PATENT DOCUMENTS

5,148,429 9/1992 Kudo et al 370/60

5,274,635 12/1993 Rahman et al 370/60.1

5,329,572 7/1994 Martens 370/60.1

5,367,522 11/1994 Otani 370/110.1

5,408,524 4/1995 Reum 370/110.1

Primary Examiner— Douglas W. Olms

A voice communication system, which is connected to a LAN to which communication terminals are connected and to a public network to which telephones are connected, is provided with a communication server between the LAN and public network having different protocols from each other. The communication server enables a voice communication between a telephone on the public network and a communication terminal connected to the LAN by performing processing similar to that for a voice communication between two communication terminals connected to the LAN. The communication server determines whether an address of the other party inputted by a user is a communication terminal address or a telephone number, and transmits a voice communication request to a communication terminal of the other party when the address is a communication terminal address. When the address is a telephone number, the user acquires the communication terminal address of the communication server, and transmits a voice communication request to the communication server. Thereafter, the voice communication processing is performed through the communication server.

21 Claims, 20 Drawing Sheets