Data transfer revisited (RFC0486)
Original Publication Date: 1973-Mar-01
Included in the Prior Art Database: 2019-Feb-12
Internet Society Requests For Comment (RFCs)
Network Working Group Bob Bressler RFC #486 BBN NIC #15064 20 March 1973
Data Transfer Revisited
A lot of work has recently gone into the development and refinement of both the RJE and FTP protocols. Stepping back from the details and small issues, we can describe the two protocols as 1) a control connection over which commands are passed, and 2) a data connection over which uninterpreted (by the server process) data is passed. Both protocols deal with the concept of identifying oneself to the server, setting up parameters, and transferring some data.
New ideas and concepts, such as the "hot card reader", have been introduced into one protocol or the other, but these concepts are generally applicable to both. In addition, a great deal of effort was made to make the structures of the two protocols be as similar as possible.
This discussion is, of course, leading to the suggestion that we stop considering these as two separate protocols, and merge them into a single unit - perhaps resurrecting the name of "data transfer".
Several advantages besides simplicity are gained by this. Sites need only build one server program - given that they can always respond with "command not implemented". This will also prevent the RJE users and servers from having to start up a (possibly) separate FTP user and server - saving the resulting doubling of programs and Telnet connections.
The further advantage of insuring that new ideas and concepts will be shared by all users and servers will also be realized. A RJE user will be able to transfer his deck of cards (file) to storage on another machine’s file system using the "hot card reader" previously defined only in the RJE protocol.
The command set of the combined protocol would now consist of several sets of command types. These sets include:
a. general system commands (e.g., USER, HELP)
b. parameter settings (e.g., TYPE, STRU)
c. data control (e.g., ABORT, REIN)
Bressler [Page 1]
RFC 486 Data Transfer Revisited March 1973
d. file operation (e.g., STOR, RETR, LIST)
e. job execution (e.g., INPUT, OUTPUT, CHANGE)
I will not try to completely specify the syntax of each command since they are still being finalized (left as an exercise for the reader?).
An implementor who was only interested in file transfer would implement the general data transfer routines and the small set of file transfer commands. Another...