Mesh-based content routing using XML

Abstract

We have developed a new approach for reliably multicasting time-critical data to heterogeneous clients over mesh-based overlay networks. To facilitate intelligent content pruning, data streams are comprised of a sequence of XML packets and forwarded by application-level XML routers. XML routers perform content-based routing of individual XML packets to other routers or clients based upon queries that describe the information needs of downstream nodes. Our PC-based XML router prototype can route an 18 Mbit per second XML stream.Our routers use a novel Diversity Control Protocol (DCP) for router-to-router and router-to-client communication. DCP reassembles a received stream of packets from one or more senders using the first copy of a packet to arrive from any sender. When each node is connected to n parents, the resulting network is resilient to (n − 1) router or independent link failures without repair. Associated mesh algorithms permit the system to recover to (n − 1) resilience after node and/or link failure. We have deployed a distributed network of XML routers that streams real-time air traffic control data. Experimental results show multiple senders improve reliability and latency when compared to tree-based networks.