Introduction

The past 5 years have seen an explosive growth in the 802.11 wireless standard. Apple first shipped the iBook [iBo] with Lucent 802.11b wireless cards under the brand name ``Airport'' in 1999. This was the first large-scale consumer deployment of 802.11 wireless technology. Since then Apple has upgraded their systems to 802.11g technology [Air]. 802.11g base stations and wireless network cards are available for under $100. Now the technology is becoming widespread, and use of wireless as the ``Last hop'' accounts for a large number of machines connected to the Internet.

In addition, high-speed DSL and Cable modems have brought 1Mbit/sec bandwidths to these same end users. Because TCP sees packet loss as an indication of congestion, any packet loss on a wireless link will lead to degraded performance and limit the effective throughput of TCP. As little as 1% packet loss can easily limit a TCP stream to under 1 Mbit.

The goal of this paper is to analyze the performance of UDP, TCP, and SCTP in a noisy wireless environment using an experimental approach. One paper [FAI] has been published on SCTP over satellite links, but nothing has yet been seen in published literature on wireless SCTP. Many papers have been done on wireless TCP, however most have depended on simulation results which ignore the complexity and interactions a real-world implementation encounters.