rfc479.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

Network Working Group                               James E. White (JEW)
Request for Comments:  479                                       SRI-ARC
NIC: 14948                                                 March 8, 1973


                     Use of FTP by the NIC Journal

   At the Network Mail Meeting (see -- 14317,) the NIC outlined it's
   requirements for implementing FTP Journal delivery and submission.

   It had always been our thinking that those two services should rely
   upon the File Transfer Protocol's MLFL command for their
   implementation.

   Prior to the meeting, we had envisioned that, in the case of
   submission, for example, the user would embed what parameters the NIC
   required (e.g., an indication that this piece of mail was to be
   journalized, a list of NIC idents, etc.) in the USERNAME field of the
   MLFL command, in a way that was transparent to his FTP user process,
   and that SRI-ARC's FTP server process would parse the 'user name' for
   the parameters and internally invoke the Journal System with them and
   the text of the mail as arguments.

      Our goal (which this scheme would have satisfied) was to provide
      the desired services while confining software changes to our own
      system and, in particular, to avoid requiring that user FTP
      processes or the File Transfer Protocol itself be modified.

   It was, however, the consensus of those present at the meeting that
   it was preferable to modify FTP in such a way that all required
   parameters could be explicitly declared, rather than require that
   they be hidden within what purported to be simply a user name.

   The intent of this RFC is to list what we (the NIC) believe were the
   new FTP commands it was agreed should be defined in support of mail
   submission and delivery. Actually, we've done some massaging after
   thinking about the issues for awhile, and so this is really a
   description of what we'd like to see included in the File Transfer
   Protocol (following the lines of thought which developed at the
   meeting), along with a short description of how the NIC would use
   them.

   Some of the commands currently make sense only if issued TO the NIC's
   FTP server process (as opposed to anybody else's) and others only if
   issued BY the NIC's FTP user process (as opposed to anybody else's).
   This is true because currently only the NIC plans to offer mail





White                                                           [Page 1]

RFC 479              Use of FTP by the NIC Journal            March 1973


   forwarding and recording (i.e., the Journal System) as a service.
   However, other hosts may in the future desire to implement a similar
   service, at which time these special commands will have wider use.

   Conceptually, all of these commands are sub-commands of a new MAIL
   command, but the intent for the moment is not to define their
   position within the FTP dialogue nor their syntax, but simply to
   describe them conceptually.  Details of syntax and use are left to
   the FTP Interest Group which meets 16-MAR-73 in Boston (see --
   14333,).

   The new sub-commands are described below.  Bracketed fields are
   optional; slash denotes a choice of two or more alternatives.

      (1)  TITLE title

         Where 'title' is a character string describing for the human
         reader the contents of the mail.

      (2)  USER-READABLE-AUTHOR author

         Where 'author' identifies the author of the mail to the human
         reader.  This may be a nickname, or any other identifier with
         which the human sender chooses to sign his mail.

      (3)  PROCESS-READABLE-AUTHOR last, first initial (ident)

         Where the author's name (and ident if known) is made available
         to the server in a form it can hope to parse (if need be).

         This sub-command is important to the NIC, providing a basis for
         locating the author in the NIC's Ident files.

      (4)  FOR-ACKNOWLEDGMENT-AUTHOR username hostname

         Where 'username' and 'hostname' define the sender in a way
         useful in acknowledging delivery (of forwarded mail).

            The acknowledgment will itself be a piece of mail sent from
            the NIC to 'username' at 'hostname'.

         It's important, conceptually, to note the NIC's unique role
         here.  Normally, acceptance of the mail by the server would
         constitute acknowledgment of delivery.  But, in the case of
         Journal submission, the NIC acts only as a forwarding agent,
         and hence delivery of mail by the sender to SRI-ARC isn't





White                                                           [Page 2]

RFC 479              Use of FTP by the NIC Journal            March 1973


         really delivery at all -- only submission.  Final delivery
         occurs when the NIC transmits a copy of the mail to each of its
         addressees; hence the need for this special kind of
         acknowledgment.

         Note that this sub-command and the previous two constitute
         different renderings of the sender's name.

      (5)  ACKNOWLEDGMENT-DETAILS
             DEFAULT / (COMPLETION / FAILURE / PERIODIC interval
                        GIVEUP time
                        TERSE / VERBOSE)

         The value of the first parameter (ignoring 'DEFAULT' for the
         moment) determines the conditions under which acknowledgment
         will be made to the sender:

            -- upon completion, whether delivery was successful or timed
            out for one or more addressees,

            -- only if delivery failed for one or more addressees, or

            -- periodically until delivery is complete.

         The value of the second parameter determines the time after
         which delivery attempts will be discontinued.

         The value of the third parameter determines how detailed -- in
         some as yet unspecified sense -- an acknowledgment will be
         returned.

            A verbose acknowledgment might, in the case of delivery
            failure, include a copy of the text of the message, or, for
            mail sent by citation (see item 10 below), a pointer to it.

         If DEFAULT is specified (in which case, FOR-ACKNOWLEDGMENT-
         AUTHOR should not be specified, and 'DEFAULT' applies to it,
         too), the NIC will extract a set of default values from its
         Ident files, provided that a PROCESS-READABLE-AUTHOR subcommand
         is present and the sender's NIC Ident can be inferred from it;
         otherwise, the NIC will apply a set of (as yet unspecified)
         system defaults.

            The NIC's Ident files will be modified to contain, for each
            user known to it, the kind of acknowledgment the user
            usually wants (i.e., his default) and the username and
            hostname that define the destination for such
            acknowledgments.  These last two pieces of information will



White                                                           [Page 3]

RFC 479              Use of FTP by the NIC Journal            March 1973


            also be used in delivering mail to the user if he has
            requested Network delivery (as opposed to Online (at the
            NIC) or hardcopy).

      (6)  ADDRESSEES-ARE name1, name2, ...

         This sub-command identifies the recipient(s) of the mail.  In
         general, 'namei' will be the name by which the recipient is
         known locally in the server's system.

         The NIC's server FTP process will permit 'namei' to be any of
         the following:

            -- a NIC Ident (designating either an individual or a
            group),

            -- username hostname, where 'username' is the name by which
            the addressee is known at host 'hostname', or

            -- lastname, firstname initial , which the NIC will attempt
            to parse and then locate in its Ident files.

         Note that now the possibility of multiple addressees is
         explicitly admitted by the Protocol, but the meaning of 'useri'
         (to the server) is left server-dependent.

      (7)  MAIL-CLASS
             BULK/POSTCARD
             SPECIAL-DELIVERY/FIRST-CLASS

         The first parameter makes a statement about the size of the
         mail, and the server may choose to use it to decide how and
         where to store he mail for the addressee.

         The second parameter makes a statement about the importance of
         the mail, and the server may choose to expedite delivery (e.g.,
         interrupt the user if he's logged in) for SPECIAL-DELIVERY
         mail.

      (8)  RECORD [identifier] [miscellaneous]

         This is the command to the server to record the mail.
         'Identifier' allows the sender the option of specifying a pre-
         assigned identifier if he has one; if this field is not
         present, the server assigns one.

         'Miscellaneous' includes any server-dependent parameters which
         the server may require or allow.



White                                                           [Page 4]

RFC 479              Use of FTP by the NIC Journal            March 1973


         When this command is issued to the NIC, it will be taken as a
         command to Journalize the mail, and 'identifier' may be:

            NIC number [RFC number]

         The NIC may allow 'miscellaneous' to contain such information
         as comments, keywords, etc.

      (9)  PRESERVED-AT hostname AS identifier

         This is not a command but a statement of fact which the FTP
         server will presumably relay to the user as it does the
         information contained in (for example) the TITLE command.

         The implication is that a copy of this piece of mail has been
         preserved at 'hostname' and is retrievable -- on a long-term
         basis -- with 'identifier'.  'Identifier' might, in general, be
         a pathname.

         When the NIC delivers Journal articles through the Net, it will
         include this sub-command, and 'identifier' will be a NIC
         number, and 'hostname' of course 'SRI-ARC' or 'NIC'.

      (10) TEXT text
           FILE pathname hostname

         One of these two sub-commands is used to actually transmit the
         mail:  the first transmits the text of the mail, the second a
         pointer to it (leaving open to the FTP server (or his user) the
         option of retrieving the text of the mail from the specified
         host).

         The NIC will transmit mail created within NLS with 'Submit
         File' using the FILE command, and mail created with 'Submit
         Message' using the TEXT command.   For mail entering the SRI-
         ARC system via its FTP server process, the NIC will employ the
         same command in delivery as was used in submission.





       [ This RFC was put into machine readable form for entry ]
      [ into the online RFC archives by Hannes Faestermann 12/97 ]







White                                                           [Page 5]