Communication system, communication method, and computer-readable recording medium

Abstract

A communication system comprising a plurality of terminals, comprising: a start request information obtaining unit that obtains information for requesting start of a session between a first terminal and a second terminal of the plurality of terminals; a session management unit that establishes the session in accordance with the start request information; a participation request information obtaining unit that obtains participation request information with which a third terminal of the plurality of terminals requests participating in the already established session; and a participation determination unit that allows the third terminal to participate or prohibit the third terminal from participating in the already established session, wherein when the participation determination unit allows participation in the already established session, the session management unit lets the third terminal to participate in the already established session.