The present invention is intended to realize high-speed and stable communication. A multi-flow RTP divides the data of one RTP session into pieces that can be transmitted through UDP ports through respectively and supplies the divided pieces of data to these ports. An RTCP controls the UDP ports through to transmit the divided data and controls a TCP port to transmit control information for reconstructing the divided data. UDP ports through receive the divided data and supplies the received data to a multi-flow RTP. An RTCP obtains the control information from the TCP port and supplies it to the multi-flow RTP. The multi-flow RTP reconstructs the divided data according to the control information and supplies the reconstructed data to the player, which reproduces the reconstructed data. The present invention is applicable to a stream data distribution system, for example.