CANS: composable, adaptive network services infrastructure
Xiaodong Fu, Weisong Shi, Anatoly Akkerman, Vijay Karamcheti · 2001
Ubiquitous access to sophisticated internet services from diverse end devices across heterogeneous net-works requires the injection of additional function-ality into the network to handle protocol conver-sion, data transcoding, and in general bridge dis-parate network portions. Several researchers have proposed infrastructures for injecting such function-ality; however, many challenges remain before these can be widely deployed. CANS is an application-level infrastructure for in-jecting application-specic components into the net-work that focuses on three such challenges: (a) ef-cient and dynamic composition of individual com-ponents; (b) distributed adaptation of injected com-ponents in response to system conditions; and (c) support for legacy applications and services. The CANS network view comprises applications, state-ful services, and data paths built from mobile soft-state objects called drivers. Both services and data paths can be dynamically created and recongured: a planning and event propagation model assists in distributed adaptation, and a exible type-based composition model dictates how new services and drivers are integrated with existing components. Legacy components plug into CANS using an inter-ception layer that virtualizes network bindings and a delegation model. This paper describes the CANS architecture, and a case study involving a shrink-wrapped client ap-plication in a dynamically changing network envi-ronment where CANS improves overall user experi-ence. 1