Abstract
Despite the explosive growth of mobile devices and applications in recent years, today's Internet provides little intrinsic support for seamless mobility. Prior solutions to addressing this problem either handle only a subset of endpoint mobility scenarios or require nontrivial changes to legacy infrastructure. In this paper, we present the design and implementation of msocket, a system that allows communicating endpoints to move across network locations arbitrarily while maintaining disruption-tolerant connectivity without any change to legacy operating systems or network infrastructure. msocket supports pre-lookup, connect-time, individual, and simultaneous mobility of one or both endpoints across multihomed network addresses, and enables seamless mobile-to-mobile communication despite the presence of address-translating middleboxes. We have implemented msocket as a user-level socket library and our evaluation shows that: (1) msocket recovers from mobility of one or both endpoint(s) in roughly two round-trips; (2) msocket's multipath scheduler greatly enhances user-perceived performance or power consumption in multihomed settings; and (3) msocket imposes little additional overhead over traditional TCP/IP sockets.