Managed file distribution on the universe network

The file distribution system on the Universe Network consists of a distributed set of co-operating agents which provide clients with a reliable bulk file collection, transfer and delivery service. The agent systems incorporate specialised techniques for optimizing use of the satellite channel, as well as making available facilities for broadcast file distribution. The distributed system architecture and protocols are described, with emphasis on the separation of control and data transfer. A detailed presentation is given of the way in which agents interact with both hosts and other agents to achieve both reliability and robustness in the face of breaks in host or network availability. A description is given of the special transfer methods used and some of the possible applications for such a system. An indication is given of possible future developments to enable evolution from an experimental to service system.