The growth of the internet has been fueled by an increasing number of sophisticated network-accessible services. Unfortunately, the high bandwidth and processing requirements of such services is at odds with current trends towards increased variation in network characteristics and a large diversity in end devices. Ubiquitous access to such services requires the injection of additional functionality into the network to handle protocol conversion, data transcoding, and in general bridge disparate portions of the physical network.

CANS is an application-level infrastructure for injecting application-specific components into the network that focuses on three challenges: (a) efficient and dynamic composition of individual components; (b) dynamic and distributed adaptation of injected components in response to system conditions; and (c) support for legacy applications and services. The network view supported by CANS consists of applications, stateful services, and data paths between them. Both services and data paths can be dynamically created and reconfigured: a planning and event propagation model assists in distributed adaptation, and a run-time type-based composition model dictates composition. It supports legacy applications and services using interception and delegation.

This talk will describe the CANS architecture and implementation, and a case study involving a shrink-wrapped client application in a dynamically changing network environment where CANS was used to improve overall user experience.