To obtain a communication system, a transmission-side communication terminal, and a reception-side communication terminal, wherein any call in pattern can be reproduced on the reception side at the initiative of the transmission side.

When a call out is made, additional information added at a transmission-side communication terminal T1 is transmitted, together with a call setting request, to a reception-side communication terminal T2 through a communication network N1. When the reception-side communication terminal T2 receives the call setting request and the additional information, the terminal T2 reproduces the received additional information as a call in pattern. The transmission-side communication terminal T1 has the initiative in transmitting the additional information as the call in pattern.