TCP performance over ATM on Linux and Windows NT

Abstract

In today's local area networks, ATM is often used as a replacement for slow Ethernet. This work measures and compares performance of the transmission control protocol (TCP) over ATM on two popular operating systems on PC hardware. Throughput and round trip latency of TCP data transfer over both Linux and Windows NT on identical hardware were measured. For throughput measurements, send and receive performances have been isolated by using a fast third-party machine as peer. Firstly, measurements indicated that high-end PC hardware can utilize the bandwidth provided by 155.52 Mbps ATM network adapters well. Running the heavyweight TCP protocol, data rates of up to 83% of the bandwidth available have been observed. As a second result, Linux and Windows NT bulk data throughput were competitive. However, particularly on slow hardware, the Linux implementation consistently outperformed NT. Finally, significant latency differences in the order of a 50% advantage for Linux were indicated by the request-response test suite.