Conclusions

This paper has presented an application-level infrastructure, CANS, for injecting application-specific functionality into the data path connecting applications and end services. Such functionality can monitor and adapt to resource changes, providing the basic support needed for building novel application-level services that can seamlessly integrate diverse end devices across heterogeneous networks. Main contributions of CANS include: (a) efficient dynamic composition of components by requiring they adhere to a restricted interface, (b) dynamic and distributed adaptation using distributed events and novel path reconfiguration algorithms, and (c) support for legacy applications and services. Our experience indicates that CANS conveniently permits dynamic deployment and distributed adaptation of application-aware components to improve user experience. CANS is one component of a larger project, Computing Communities, which focuses on distribution middleware for legacy applications. Our future work involves integrating CANS with related efforts emphasizing resource management and security issues, improving its performance, and designing better planning algorithms.