Provided is a communication system including a first, a second, a third, and a fourth apparatuses, in which the first and the second apparatuses communicate with each other over a first communication service, and the third and the fourth apparatuses communicate with each other over a second communication service. The first apparatus has a first communication means, a setup information obtaining means, and a first connection requesting means. The second apparatus has a second communication means, and a second connection requesting means. The third apparatus has a third communication means, and a setup information sending means. The fourth apparatus has a fourth communication means and a connection processing means. |