RFC 491 (rfc491) - Page 1 of 2

What is "Free"?

Network Working Group                                    M. A. Padlipsky
Request for Comments: 491                                    MIT-Multics
NIC: 15356                                                 12 April 1973


                              What Is Free

   In at least three of the RFC's about "mail" and the File Transfer
   Protocol (RFC's 454, 475, 479), something very like the following is
   asserted: "Network mail should be free; i.e., no login or USER
   command should be required."  Unfortunately, "i.e" (=that is) is
   misleading.  It simply does not follow to imply that the only way
   mail can be free is for it not to require a login; explicit login on
   a free account would of course also work.  Indeed, depending upon
   per-Host idiosyncrasies in the Logger / Answering Service / process
   creation environment, an explicit login may well prove to be far more
   natural than an implicit login.  (Even in environments where implicit
   login is easy, surely explicit login is just easy.)  Granted, login
   on a free account requires users to remember the name of the free
   account.  However, this would not be too great a burden to bear if
   there were reasons for preferring an explicit login and if the free
   account had the same name on all Hosts.  Therefore, from the promise
   that Network protocols should not implicitly legislate "unnatural"
   implementations for participating Hosts if it is conveniently
   avoidable, I propose the following formulation:

      Network mail should be free.  Network mail should not require
      users to remember the name of the free account on a given system.
      I.e., it should either be "loginless" or it should take the same
      login everywhere.  But some systems need/want/prefer a login.
      Therefore, USER NETML / PASS NETML should be made to work
      everywhere for free mail.

         Note: "NETML" is fewer than six characters and is upper case
         hence, it should fit in the least common denominator category
         of user identifiers, but it's still long enough not to conflict
         with anybody's initials (in all probability).

   Now, because of the implementation implications this may all sound
   like special pleading, but I claim that another implication of the
   "incorrect" formulation will further show the superiority of an
   explicit login for mail.  For the "loginless" view leads to problems
   in regard to the authentication aspects of login and the accounting
   aspects, by apparently assuming that the sole purpose of login is to
   initiate accounting.  In RFC 475, the problem is exposed when, after
   noting that some systems allow access control to be applied to
   mailboxes, it is asserted that FTP USER command is wrong for access
   control because you'd then be on the free account and a new FTP FROM



Padlipsky