The software architecture and interprocess communications of IRI: an Internet-based interactive distance learning system

Discusses the software architecture, interprocess communication and the reference implementation of the Interactive Remote Instruction (IRI) system for distance learning. IRI is an Internet-based system which integrates continuous multimedia, shared applications and a variety of multi-user collaborative utilities. Internet multicasting is used by IRI for group management and data sharing, UDP (Unix domain protocol) multicasting is used for audio and video streams, while a reliable multicasting protocol (RMP) is used by XTV, the data sharing engine of IRI. The system is both scalable and expandable. It is scalable through the use of multicasting for interprocess communication. It is expandable due to its partitioning into a set of autonomous but cooperating components. The interaction among components is specified by a set of messages and the functions needed to send and receive these messages.