ALLNODE-RT: a real time, fault tolerant network

This paper presents a proposed multi-stage switching network for real-time systems which features: priority scheduling scalability, high bandwidth, low latency, fault tolerance, and breaking of lower priority connections. The fault-tolerant approach presented gives continuous availability in the presence of many failures, and the correction time is so rapid that real-time messages can be delivered before their deadlines expire. This is possible because the ALLNODE-RT Network contains numerous alternate paths between any two nodes. The ALLNODE-RT hardware searches for an available, non-failed path and guarantees the meeting of a deadline by dynamically increasing priority as the deadline approaches and breaking lower priority connections. The network is based on the existing ALLNODE Switch concept. The modifications required to evolve to a real-time switch are described, as well as the fault tolerance concepts