What would be the best approach to designing a real time Client based application that needs streaming data from a remote Windows based server. Something like a Stock Trading Application. Curently looking at WCF Callbacks OR Direct DB Connection. Main concerns are bandwidth, reliable connections and concurrent users into the 5-6K range. Data is text only and realtime is subjective (Less than a minute for all clients apps to be updated) Would likely be built on WPF and SQL Server 2008.