Avoiding congestion collapse on the Internet using TCP tunnels

Abstract

This paper discusses the application of TCP tunnels on the Internet and how Internet traffic can benefit from the congestion control mechanism of the tunnels. Primarily, we show the TCP tunnels offer TCP-friendly flows protection from TCP-unfriendly traffic. TCP tunnels also reduce the many flows situation on the Internet to that of a few flows. In addition, TCP tunnels eliminate unnecessary packet loss in the core routers of the congested backbones, which waste precious bandwidth leading to congestion collapse due to unresponsive UDP flows. We finally highlight that the use of TCP tunnels can, in principle, help prevent certain forms of congestion collapse described by Floyd and Fall [IEEE/ACM Trans Networking 7 (4) (1999) 458]. The deployment of TCP tunnels on the Internet and the issues involved are also discussed and we conclude that with the recent RFC2309 recommendation of using random early drop as the default packet-drop policy in Internet routers, coupled with the implementation of a pure tunnel environment on backbone networks makes the deployment of TCP tunnels a feasible endeavour worthy of further investigation. © 2002 Elsevier Science B.V. All rights reserved.