28 - The Evolution of File Transfer Protocol

Abstract

File Transfer Protocol (FTP)is one of the first application protocols designed for an interoperable internetwork. It started out as a set of basic file management protocol commands; implementers have used those commands to create FTP implementations that have grown increasingly easy to use. Intitially, FTP programs required the use of commands that mirrored command line file management on the host system; if you could manipulate files on that host, you could also manipulate files on that host from a remote host. Implementers were relatively slow to build appropriate graphical user interface (GUIs) for FTP, merely translating commands to pulldown menus at first. However, by the late 1990s, GUI FTP programs were available that could be easily, and transparently, used by non-expert users. Most products change and improve over the years: automobiles no longer include a hand-cranked starter; mobile telephone service prices spiral downward as service billing grows simpler. FTP has not only become easier to use, but has also been modified to make it work more smoothly: hosts need not permit inbound connections from servers for downloads, for example. Likewise, some artifacts of less than great product features, such as the VCR's continuously flashing unset clock and FTP's support for proxy file transfers, take longer to fix or replace. Although many, if not most, of the applications for which FTP was important in 1983 are now performed with more modern protocols, newer technologies rarely eradicate older ones entirely.