A transmitting party adds reproduction time information to each transport packet to form an extended transport packet, encapsulates the extended transport packet, adds capsule counter information, and transmits the capsule. A receiving party has a storage means, and transmits a re-send request including the capsule count information to the transmitting party when a packet loss occurs. At the receiving party, the re-sent data received overwrites data in its original storage region. At reproduction, the receiving party decodes the data after compensating for jitter referring to reproduction time information. Accordingly, a packet loss or jitter is compensated for at both transmitting and receiving parties in a communications network such as the Internet so as to prevent the occurrence of a decoding error at the receiving party.