System Support for Bandwidth Management and Content Adaptation in Internet Applications

This paper describes the implementation and evaluation of an operating system module, the Congestion Manager (CM), which provides integrated network ow manage- ment and exports a convenient programming interface that allows applications to be notied of, and adapt to, changing network conditions. We describe the API by which applications interface with the CM, and the archi- tectural considerations that factored into the design. To evaluate the architecture and API, we describe our im- plementations of TCP; a streaming layered audio/video application; and an interactive audio application using the CM, and show that they achieve adaptive behavior without incurring much end-system overhead. All ows including TCP benet from the sharing of congestion information, and applications are able to incorporate new functionality such as congestion control and adap- tive behavior.