System Support for Bandwidth Management and Content Adaptation in Internet Applications

TL;DR

This paper presents the Congestion Manager, an OS module that manages network flows and enables applications to adapt to network conditions, improving performance and functionality with minimal overhead.

Contribution

Introduction of the Congestion Manager API and architecture, allowing applications to efficiently adapt to network congestion and share congestion information.

Findings

TCP and applications achieve adaptive behavior

Flows benefit from shared congestion information

Minimal end-system overhead observed

Abstract

This paper describes the implementation and evaluation of an operating system module, the Congestion Manager (CM), which provides integrated network flow management and exports a convenient programming interface that allows applications to be notified of, and adapt to, changing network conditions. We describe the API by which applications interface with the CM, and the architectural considerations that factored into the design. To evaluate the architecture and API, we describe our implementations 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 flows including TCP benefit from the sharing of congestion information, and applications are able to incorporate new functionality such as congestion control and adaptive behavior.