Files2u

Files2U (F2U) is a proprietary application layer protocol, based on TCP/IP. F2U combines various application layer protocols including HTTP, FTP and SMTP to offer a single system to transfer large files through the internet. F2U protocol is used by an application server called Files2U. The new generation of F2U can also use UDP at the Transport layer. The use of UDP packets overcomes latency issues and packet loss. Forward Error Correction built into the new version of F2U protocol allows for dropped packets or reordering of packets. This makes it extremely useful to transfer large files where network conditions are poor. Files2U is deployed worldwide in various government, military and commercial instances. APIs are available on F2U to develop custom applications or alternatively use Files2U application for web-based file transfers.

Objectives of F2U

The objective of F2U as outlined by its specifications are the following:
# Promote easy sharing of large files
# Be seamless to the end user
# Provide enhanced security and authentication
# Be firewall and proxy friendly

History and Development of F2U

Files2U has been developed independently by various groups that managed to combine the versatility of FTP, the easy of use of HTTP and the availability of SMTP. The combining of three protocols into one has led to a single protocol that can handle large file transfers in a secure and easy manner. The new generation of F2U protocol supports UDP at the Transport layer as well as TCP. TCP has an inherent quality control mechanism that allows for packet ordering and minor packet loss (up to 2%). This inherent mechanism works well in wired networks but when network conditions are poor such as intercontinental transfers or wireless networks, TCP’s effective throughput is low. UDP on the other hand works well in such network conditions, but doesn’t compensate for actual lost packets. To over come this issue of packet loss, F2U supports forward error correction. This offers a fast protocol with no call back channel where packets can be dropped or rearranged without significant loss to the speed at which data is transferred.

F2U and Web-Browsers

F2U protocol is supported by most new web-browsers including Internet Explorer v4.0 and above. The F2U system also needs a JVM to operate.

Security and Encryption

F2U protocol can be deployed using an SSL certificate. This allows F2U to wrap over HTTP. If an SSL certificate is used then the transmission is carried encrypted over HTTPs. This adds a slight overhead (5%) over the traffic data but offers encryption at an industry-standard level. If the new generation of F2U is used, then UDP packets are encrypted using Digital Fountain’s Raptor Codes. At the application level, Files2U application supports further authentication and authorization procedures that guarantee delivery to the recipient.

Short comings and Criticism

The blending of 3 application protocols to comprise a single application system has led to overhead in the packet-size. With an overhead of 3-5%, the over all transfer of data is slightly inefficient with F2U protocol. At the application level, Files2U supports reporting and logging. However this has been criticized for not being verbose enough.

See also

* FTP
* HTTP
* SMTP
* FTP servers
* Shared file access
* TCP
* UDP
* HTTP proxy
* Web server
* Extended SMTP (ESMTP)

F2U similar protocols

* FTPS (FTP/SSL), FTP run over SSL
* Secure Copy (SCP), a protocol running over SSH
* Simple File Transfer Protocol (SFTP), the historic protocol RFC 913
* SSH file transfer protocol (SFTP, SH-FTP, FTP/SSH), a protocol running over SSH
* Trivial File Transfer Protocol (TFTP)

oftware

* Comparison of FTP client software
* List of FTP server software
* FastSCP SSH-FTP tool
* [http://www.ssh.com/support/documentation/online/ssh/winhelp/32/Forwarding_FTP.html Technical description of FTP forwarding mode in SSH Tectia software]