XO: XMPP overlay service for distributed chat

This work discusses the adaptation of group-oriented messaging and chat technology for operation in serverless, multicast-capable mobile wireless architectures. The main goals are to allow group messaging and chat sessions to fragment/coalesce, operate through disrupted TCP conditions, and improve bandwidth utilization when multicast is available. In addition, the solution demonstrates proxying and gateway methods to interoperate with existing client and server standards and software. The approach presents several innovations that extend and adapt extensible Messaging and Presence Protocol (XMPP) standards for incorporating group serverless chat and messaging within more challenging operational environments. While there is large body of work on messaging middleware solutions, this paper concentrates on the adaptation of specific XMPP standards for serverless, multicast operation. We discuss our working implementation prototype and present initial experimentation comparing client/server multi-user chat (MUC) operation to serverless multicast MUC within several mobile network scenarios. In addition, we demonstrate a gatewaying solution for serverless MUC systems to interoperate with conventional MUC server-based systems. The specific test scenarios are instrumented to operate within a wireless mobile emulation environment using mobile ad hoc network (MANET) unicast and multicast routing technology. This approach remains independent of any particular routing algorithm and the proxied XMPP protocol module allows for the deployment of existing real-world client software across all nodes of the network. The initial findings show the significant performance potential for serverless MUC extensions. In addition to these results, we discuss some ongoing design challenges and future planned work.