In this demonstration, we present a prototype content-based dissemination broker, called Sonnet, which is built upon structured overlay network. It combines approximate filtering of XML packets with routing in the overlay network. Deliberate optimization technologies are implemented. The running and tracing of the system in a real-life application are to be demonstrated. Categories and Subject Descriptors H.2.4 [Database Management]: Systems--distributed databases, query processing; H.3.3 [Information Storage and Retrieval]: Information Search and Retireval--information filtering; H.3.4 [Information Storage and Retrieval]: Systems and Software--distributed systems, selective dissemination of information?SDI General Terms Design Keywords Distributed publish/subscribe, XML data dissemination, approximate filtering, path digest