A transmitting-end terminal device transmits an electronic mail including large-size data such as video data to a transmitting-end cache via a transmitting-end router. The transmitting-end cache temporarily stores the received data. A POB server authenticates a user of the transmitting-end terminal device...http://www.google.ca/patents/US7231658?utm_source=gb-gplus-sharePatent US7231658 - Data transmission system, apparatus and method for processing information, apparatus and method for relaying data, storage medium, and program
