[Problem] Provided is a relaying device that can track and record a communicated voice of a specific communication terminal using a mixing function of the relaying device.
[Solution] When a communication terminal has sent a call packet to call another at least one communication terminal, a communication session in which this communication terminal that has made a call and a communication terminal that has been called are participating terminals is established. In the communication session, voice communication is relayed by transferring a voice signal which is transmitted from the participating terminals to another at least one communication terminal. A virtual device is registered as a participating terminal of the communication session and the voice signal which is transmitted from the communication session to the virtual device is recorded in the relaying device.