A gateway for an internet telephone system manages calls to and from personal computers and enables the personal computers to use the internet telephone system with an IP address assigned by a DHCP server or a private IP address. The gateway has a LAN receiver for processing an incoming call from the Internet or a personal computer, a line transmitter for processing an outgoing call to a telephone according to a request from the LAN receiver, a line receiver for processing an incoming call from a telephone, a LAN transmitter for processing an outgoing call to the Internet or a personal computer according to a request from the line receiver, and a logger for logging information about calls according to requests from the LAN transmitter and line transmitter. If the LAN receiver receives an incoming call from a LAN and if the incoming call accompanies an IP address as a receiver address, the LAN receiver requests the LAN transmitter to make a call based on the incoming call, and the LAN transmitter requests the logger to log information about the call.