CONTROL SYSTEM, COMMUNICATION SYSTEM, CONTROL METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To solve the problem in which in a case where a new communication terminal is let to participate in a session in which content data is transmitted between communication terminals via a plurality of relay devices, if the plurality of relay devices include a relay device which a control device performing participation control cannot access, the control device cannot transmit a notification of participation of the new communication terminal to the relay device; and thus, a relay device side cannot set a new transmission path of the content data.SOLUTION: When a control device 50 establishes a session for transmitting content data between communication terminals via a plurality of relay devices 30, it selects a relay device 30 that manages a destination of the content data in the session from the plurality of relay devices 30, and transmits a relay device ID of the selected relay device to a relay device 30 that is the connection destination of a terminal 10 participating in the session.SELECTED DRAWING: Figure 1