Multi connection TCP mechanism for high performance transport in an ATM Network

Abstract

This paper proposes a new transport mechanism, multi-connection TCP, for high-speed and long delay networks. With to the appearance of ATM network services, wide area data communication networks(WANs) are becoming faster and more world wide oriented. In this situation, the performance of window-based, flow-controlled and connection-oriented transport protocols, such as TCP, is degraded far from the optimum. The throughput of TCP is limited by its window size and round trip delay time(RTT), and the ideal throughput of TCP with 641(byte maximum window size over a trans-Pacific ocean link such as TPC-4 is only about 2.6Mbps for a 45Mbps DS3 line with 200ms RTT. In order to achieve high throughput of inter-LAN communications via a high speed, long delay WAN, such as B-ISDN, we propose a mufti connection TCP, and verify its performance by applying it to FTP. A multi-connection FTP can establish up to 16 connections simultaneously, and transfer the data in parallel. The experiment shows multi connection TCP (16 connections and 24Kbytes of each window size ) achieves about 8.5Mbps end-to-end throughput via an emulated OC3 I55Mbps WAN with 200ms RTT.