PHILAN: a LAN providing a reliable message service for distributed processing

摘要

A local area network (LAN) design based on a ring topology is presented which can support both packet-switched and circuit-switched traffic. The packet-switching service is reliable in that the LAN controllers deal with all protocol problems, i.e., medium arbitrations as well as flow and error control. The service can meet real-time constraints, since the performance is stable under high load conditions and the arbitration delays are bounded. Moreover, the processing speed of the LAN controller is independent of the transmission speed, and the speed requirements are such that they can be met by a microprocessor (no need for dedicated hardware to process the information on the fly). Before the design of PHILAN is presented, an analysis is given of the protocol problems that have to be dealt with when establishing a reliable packet-switching service on a LAN.