Described herein is a method of controlling data flow between a local network (120) and a remote network (30) via a geostationary satellite link (40, 46, 48). The local network (120) comprises a sending host (22) and a connection splitting node (124) which includes a throttling unit (150). The remote network (30) comprises a receiving host (32) which is connected to a second connection splitting node (142) having a buffer (152) via the internet (34). The data flow rate from the local network (120) is throttled to provide a data flow rate which substantially matches that which can be handled by the remote network (30) so that the buffer (152) at the second connection splitting node (142) is not overfilled.