We have developed a new approach for reliably multicasting timecritical 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 contentbased routing of individual XML packets to other touters 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.
In REF , each node is an XML router, and XML documents are routed through the network.
Mesh-based content routing using XML
SOSP '01
Computer Science