| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that it is necessary to provide a chat server for managing a chat in order to perform a chat between terminals, causing the insufficiency of economic efficiency.SOLUTION: In a chat system in which a chat is performed between user terminals by peer-to-peer by using a key telephone device to which a plurality of user terminals are connected, an IP address of each user terminal is received by the key telephone device in a state that the IP address is included in presence information, and the key telephone device refers to a list corresponding to the IP address, and transmits the presence information including the received IP address to a transmission destination in the list, and the chat is performed by peer-to-peer between the user terminals afterwards, and when the user device during the chat is changed to the other user device, the presence information including the IP address of the other user terminal is transmitted to the key telephone device, and the chat is continued, and chat data are transferred by peer-to-peer between the user device and the other user device. |
