Improved TCP performance over long-delay and error-prone links

The enormous growth in Internet use has led to a desire to provide efficient transfer over a variety of delivery technologies. However, using TCP as the transport layer can conflict with the physical characteristics of those links, severely limiting the efficiency of delivery. Work undertaken by Roke Manor Research Ltd has resulted in the development of enhancer technology that can dramatically improve throughput and efficiency. This paper describes the work undertaken and compares the results with standard TCP and TCP with satellite-friendly options. The problem of using TCP over long latency links is described and connection splitting is introduced as a solution to this problem. The various issues that are raised by the introduction of enhancers into the end-to-end path are then discussed. Results are introduced to show the benefits of protocol enhancement in realistic deployments and to measure absolute performance. Testing has showed that it is possible to split TCP connections with little or no damage to the underlying protocols and achieve significant increases in performance.