NWG/RFC 385 Abhay K. Bhushan NIC 11357 MIT-MAC Updates: RFC 354 August 18, 1972 RFC 354
The following comments pertain to the File Transfer Protocol, NWG/RFC 354. The comments include errata, further discussion, emphasis points, and additions to the protocol. I shall incorporate these comments into the main protocol document after we have had sufficient experience.
(i) Page 2, line 15: replace user-FTP by server-FTP. (ii) Page 3, line 12: replace III.A by III.C. (iii) Page 15, last para, line 1: replace user s by user is. (iv) Page 28, line 21: replace _CRCRLF_ by _CRLF_. (v) Page 27, line 10: replace 451,451 by 451. (vi) Note that on Page 26, line 15 mode code is S|B|T|H.
Type - ASCII (8-bit bytes)
Mode - Stream
Structure - File
Commands - RETR, STOR, USER (and PASS), SOCK and BYE
BCDIC - The sender transfers data using the EBCDIC
character code and 8-bit transfer byte size.
The _CRLF_ convention is used for vertical format
control. This type will be used for efficient
transfer of EBCDIC files between systems which
use EBCDIC for their internal character
representation.
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EBCDIC with ASA vertical format control - This is the EBCDIC Print File defined in RFC 354. The server is to transform the data in accordance with ASA (Fortran) vertical format control standards but using the EBCDIC character code. The data is to be transferred in 8-bit bytes.
The new types are to be denoted by symbols E for EBCDIC, P
for Print file-ASCII and F for Formatted (ASA standard)
EBCDIC print file. A discussion of the ASA vertical format
control appears in NWG/RFC 189, Appendix C, and in
Communications of the ACM, Vol 7, No. 10, p. 606, October
1964. According to the ASA vertical format control
standards, the first character of a formatted record is not
printed but determines vertical spacing as follows:
Character Vertical Spacing before printing --------- -------------------------------- Blank One line 0 Two lines 1 To first line of next page + No advance
In addition to the above four, there are more characters (defined in Appendix C, RFC 189) which represent an IBM extension to the ASA standard.
The disadvantages are:
1) The EOF by closing the connection is not reliable.
2) The EOR by ASCII _CRLF_ is unreliable as the _CRLF_ really may be valid data rather than an EOR. It is an EOR only if the sender and receiver have a _prior_ agreement to that effect.
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454 FTP: Cannot connect to your data socket.
This is a fail response any of the commands requiring data transfer (including RETR, STOR, APPE, and LIST)
MLFL <user>CRLF
where
<user> ::= <empty>| <NIC ident>| <sys ident>
If the user field is empty or blank (one or more spaces),
then the mail is destined for a printer or other designated
place for site mail. <NIC ident> refers to the standard
identification described in the NIC Directory of Network
Participant. A serving host may keep a table mapping <NIC
ident> into <sys ident>. This would provide for uniform
convenient usage. <sys ident> is the user's normal
identification at the serving HOST. The use of <sys ident>
would allow a network user to send mail to other users who
do not have NIC identification but whose <sys ident> is
known.
The intent of this command is to enable a user at the user
site to mail data (in form of a file) to another user at the
server site. It should be noted that the files to be mailed
are transmitted via the data connection in ASCII type.
These files should be appended to the destination user's
mail by the server in accordance with serving Host mail
conventions. The mail my be marked as sent from the
particular using HOST and the user specified by the 'USER'
command. The reply codes for the "MLFL" command are
identical to that in the "APPE" command, as shown below:
COMMAND SUCCESS FAIL ------- ------- ---- MLFL 250 451,454,500-506 Sec. reply 252 452,453
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MAIL <user>CRLF
the syntax of <user> is identical to that in the MLFL command described above. After the 'MAIL' command is received, the server is to treat the following lines as text of the mail sent by the user. The mail text is to be terminated by a line containing only a single period, that is the character sequence ".CRLF" in a new line. The following new reply codes are defined to handle the mail command:
350 Enter mail, terminate by a line with only a '.' 256 Mail completed.
The reply codes are:
COMMAND SUCCESS FAIL ------- ------- ---- MAIL 350 450,451,500-506 Sec Reply 256
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[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by BBN Corp. under the ] [ direction of Alex McKenzie. 1/97 ]
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