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Stephen Hemminger - Linux Foundation

TCP congestion testing - Preventing global Internet warming - RESCHEDULED MON 16:30 CHURCHILL D

TCP/IP is the backbone of the Internet and one of the most critical parts of the Linux kernel. Because of the efforts of many researchers, Linux has the fastest and most flexible TCP implementation. But there is no commonly used test environment for research and validation of performance and fairness. The pieces for constructing a test bed are available, but there is no overall coordination. Each researcher that studies TCP congestion control has built test tools, scripts, and infrastructure, but their environment is a "one off" and thrown away after the paper is written. Developers often invest significant effort in setting up their test environment, but overlook important details that invalidate their efforts.

The lack of a testing framework has led to a number of problems. Several congestion control algorithms deployed in early versions of Linux 2.6 had performance problems that were not found until a year after release. This led the Internet standards body (IETF) to be distrustful of newer congestion control algorithms and Linux in general. My goal is to get a common platform for community participation and regression testing.

This project documents the work integrating the tests done by Hamilton Institute (Ireland) and North Carolina State University and others into a test framework. A package will be available that allows multi-machine (WAN in basement) or single-machine using virtualization (WAN in a box) test setups. Other projects may find this environment useful as well: it could be used for NFS and VOIP development and kernel benchmarking.

The paper will cover the results for Linux 2.6.22 TCP congestion control protocols. If time permits, I will include results comparing results in the emulated environment with the WAN in a lab network at UCLA.

Submitted paper

Paper (PDF) and Paper (tgz) .