A video data providing unit (10) connects to a restricted access
providing-side VPN (20). A streaming server (60) connects to a restricted
access transmitting-side VPN (50). A router (40) determines whether or
not transmitting-side data such as request data or instruction data
received via the transmitting-side VPN (50) is data that has been
transmitted from the streaming server (60), and whether or not
providing-side data such as video data received via the providing-side
VPN (20) is data that has been transmitted from the information providing
unit (10). The router 40 then transfers the transmitting-side data and
providing-side data based on those determination results.