RFC 114 (rfc114) - Page 1 of 17

File Transfer Protocol

Network Working Group                                         A. Bhushan
Request for Comments: 114                                MIT Project MAC
NIC: 5823                                                  16 April 1971


                        A FILE TRANSFER PROTOCOL


I. Introduction

   Computer network usage may be divided into two broad categories --
   direct and indirect.  Direct usage implies that you, the network
   user, are "logged" into a remote host and use it as a local user.
   You interact with the remote system via a terminal (teletypewriter,
   graphics console) or a computer.  Differences in terminal
   characteristics are handled by host system programs, in accordance
   with standard protocols (such as TELNET (RFC 97) for teletypewriter
   communications, NETRJS (RFC 88) for remote job entry).  You, however,
   have to know the different conventions of remote systems, in order to
   use them.

   Indirect usage, by contrast, does not require that you explicitly log
   into a remote system or even know how to "use" the remote system.  An
   intermediate process makes most of the differences in commands and
   conventions invisible to you.  For example, you need only know a
   standard set of network file transfer commands for your local system
   in order to utilize remote file system.  This assumes the existence
   of a network file transfer process at each host cooperating via a
   common protocol.

   Indirect use is not limited to file transfers.  It may include
   execution of programs in remote hosts and the transfer of core
   images.  The extended file transfer protocol would facilitate the
   exchange of programs and data between computers, the use of storage
   and file handling capabilities of other computers (possibly including
   the trillion-bit store data computer), and have programs in remote
   hosts operate on your input and return an output.

   The protocol described herein has been developed for immediate
   implementation on two hosts at MIT, the GE645/Multics and the PDP-
   10/DM/CG-ITS (and possibly Harvard's PDP-10).  An interim version
   with limited capabilities is currently in the debugging stage. [1]
   Since our implementation involves two dissimilar systems (Multics is
   a "service" system, ITS is not) with different file systems (Multics
   provides elaborate access controls, ITS provides none), we feel that
   the file transfer mechanisms proposed are generalizable.  In
   addition, our specification reflects a consideration of other file
   systems on the network.  We conducted a survey [2] of network host



Bhushan