The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 04, 2002
Filed:
May. 26, 1998
Yasubumi Chimura, Tokyo, JP;
Masanori Goto, Tokyo, JP;
Mitsuo Endou, Tokyo, JP;
Toshikatsu Nakajima, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
A telephone communication method capable of promoting the efficient use of the limited number of IP (Internet Protocol) addresses is disclosed. When a call is originated on a first telephone terminal, a first gateway accommodating the terminal accesses a DNS (Domain Name System) server via a UDP (User Datagram Protocol) channel of Internet or Intranet. The first gateway inquires the DNS server of the IP address of a second gateway accommodating a telephone terminal to be called, using an office number assigned to the second telephone terminal as a host name. The DNS server returns the IP address of the second gateway to the first gateway via the UDP channel. In response, the first gateway selects its own IP address for speech transfer and sends a call connection request to the second gateway on a TCP (Transmission Control Protocol) channel of Internet. On receiving the request, the second gateway determines whether or not the second telephone terminal is busy, and selects the IP address for speech transfer if it is idle. The IP address selected is returned to the first gateway in the form of a response message. As a result, a connection is set up between the two telephone terminals.