Comments on the File Transfer Protocol (RFC0385)
Original Publication Date: 1972-Aug-01
Included in the Prior Art Database: 2019-Feb-12
Internet Society Requests For Comment (RFCs)
NWG/RFC 385 Abhay K. Bhushan NIC 11357 MIT-MAC Updates: RFC 354 August 18, 1972 RFC 354
COMMENTS ON THE FILE TRANSFER PROTOCOL (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.
1. Please note the following corrections: (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.
2. The language of RFC 354 reads that it is recommended for hosts to implement the default parameters. The sense of the word recommended should be taken as required. Thus the required minimum implementations for FTP servers is:
Type - ASCII (8-bit bytes) Mode - Stream Structure - File Commands - RETR, STOR, USER (and PASS), SOCK and BYE
3. The "Print File-ASCII" and "EBCIDIC Print File" types are incorrectly specified (pages 10 and 11, RFC 354). The real problem with print files is of ASA (Fortran) vertical format control. Instead of the two print file types, there should really be three types as described below:
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.
NWG/RFC 385 Page 2
ASCII with ASA vertical format Control - This is the "Print file-ASCII" defined in RFC 354. The server is to transform the data in accordance with ASA (Fortran) vertical format control procedures for printing on printers that still use this standard. The data is to be transferred as 8-bit bytes.
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 characte...