DDFTP: Dual-Direction FTP

This paper proposes a fast and efficient concurrent technique for downloading large files from replicated FTP servers available over the Internet, Cloud and Grid environments. This technique utilizes the availability of replicated FTP servers to enhance file download times through concurrent downloads of file blocks. As this technique enhances the download time, it imposes no extra communication and processing overhead compared to other concurrent or parallel FTP techniques. The proposed technique requires no coordination between servers and relies on the features of TCP to provide an efficient load balancing mechanism among multiple heterogeneous replicated FTP servers. This mechanism also provides an efficient load balancing solution to efficiently utilize available network and server resources on dynamic environments with varying network and FTP servers´ loads. The proposed technique has been implemented and evaluated and the results show considerable performance gains for file downloading compared to other approaches.