Software distribution by reliable multicast

Network layer protocols such as the Internet protocol (IP) offer an unreliable, best-effort multicast datagram service in internetworks. In order to use this point-to-multipoint communication service for the software update of peripheral file servers, it has to be enhanced to guarantee a reliable delivery of files. While many other multicast applications have less stringent reliability requirements it is essential for this application that either peripheral file servers receive a file correctly, or a failure can be detected and signalled to the user. We propose an end-to-end application layer protocol building on top of a thin transport layer (UDP) and a best-effort network layer multicast service (IP), that delivers such a service and is geared towards the use in heterogeneous campus area networks. It employs sender-based implosion avoidance, and rate-based flow control in order to adapt to changing network conditions.