I. Introduction
Recently, high-speed networks are connected each other using the optical technologies. So, network bandwidth is expanded to several tens of Gb/s which enable data intensive applications that were impossible in the past. That is, various new researches are in progressed, in which demand a large-scale data transmission, such as the study on nuclear fusion, synoptic correlation research, and high energy physics, and etc. Traditionally, most of these applications make use TCP mechanism as a transmission protocol.