The IP network represented by the Internet is growing rapidly, and VoIP (Vo
ice over IF) technology stands increasing part of telephone communications
now. Corporate network systems are also beginning to use the IP technology
to integrate data and voice communications. This paper introduces the Team
Collaboration Support System " TCOLLABO," which uses the IP technology for
new communication services and computer applications. The system adapts the
VoIP technology, which was mainly used in WAN environments, to the desktop
telephones used by businesses communication.