Measuring Round Trip Time and File Download Time of FTP Servers

Today, Internet is a public, cooperative, and self-sustaining facility accessible to hundreds of millions of people worldwide. It has made the world a global village. It uses a layered model such as TCP/IP. Data can transfer easily using ordinary file transfer method such as HTTP and emails protocols. When to transfer or download the large set of data like big collection of file via inexpensive IP networks then throughput collapses. New TCP stacks and new network acceleration devices are market to help .but fail to fully utilize many wide area network paths. Consequently, conventional FTP, and even new "acceleration" solutions, cannot provide the speed and predictability needed for global file transfers. There are some problems which may affect the download time. It may include the hardware/software configurations, location of machines, bandwidth, delay, congestion, size of the files and other type of configurations problems. The response time of the FTP server and Round Trip Time (RTT) plays an important role in download time of a file. In this paper, we investigate the possible relationship between the Round Trip Time and the software download time for the FTP servers. It also shows the factors that could have an impact on the FTP server response time. In our experiment, we assume the existing infrastructure of the Internet with its current technologies and protocols. So we concluded that if the RTT is less, the download time will be less. We presented the Karn’s algorithm to improve the accuracy of RTT measurement. Keywords: File transport protocol, Round trip time, Karn’s algorithm, DNS response time, TCP/I