SDI Seminar

Speaker: Jeff Semke, Pittsburgh Supercomputing Center
Date: August 20, 1998 Time: 1 p.m.
Place: Wean Hall 8220

Automatic TCP Buffer Tuning

Jeffrey Semke, Jamshid Mahdavi, and Matthew Mathis, "Automatic TCP Buffer Tuning", Computer Communications Review, a publication of ACM SIGCOMM, volume 28, number 4, October 1998.


With the growth of high performance networking, a single host may have simultaneous connections that vary in bandwidth by as many as six orders of magnitude. We identify requirements for an automatically-tuning TCP to achieve maximum throughput across all connections simultaneously within the resource limits of the sender. Our auto-tuning TCP implementation makes use of several existing technologies and adds dynamically adjusting socket buffers to achieve maximum transfer rates on each connection without manual configuration.

Our implementation involved slight modifications to a BSD-based socket interface and TCP stack. With these modifications, we achieved drastic improvements in performance over large bandwidth*delay paths compared to the default system configuration, and a significant reduction in memory usage compared to hand-tuned connections, allowing many more simultaneous connections.