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Revised FTP reply codes (RFC0640)

IP.com Disclosure Number: IPCOM000003712D
Original Publication Date: 1974-Jun-19
Included in the Prior Art Database: 2000-Sep-13
Document File: 13 page(s) / 39K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Postel: AUTHOR

Abstract

Jon Postel 19 JUN 75

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 7% of the total text.

NWG/RFC# 640 JBP NJN 5-JUN-74 16:07 30843

Revised FTP Reply Codes

Jon Postel

19 JUN 75

Revised FTP Reply Codes 1

This document describes a revised set of reply codes for the File

Transfer Protocol. 2

The aim of this revision is to satisfy the goal of using reply

codes to enable the command issuing process to easily determine

the outcome of each command. The user protocol interpreter should

be able to determine the success or failure of a command by

examining the first digit of the reply code. 3

An important change in the sequencing of commands and replies

which may not be obvious in the following documents concerns the

establishment of the data connection. 4

In the previous FTP specifications when an actual transfer

command (STOR, RETR, APPE, LIST, NLIST, MLFL) was issued the

preliminary reply was sent after the data connection was

established. This presented a problem for some user protocol

interpreters which had difficulty monitoring two connections

asynchronously. 4a

The current specification is that the preliminary reply to the

actual transfer commands indicates that the file can be

transferred and either the connection was previously

established or an attempt is about to be made to establish the

data connection. 4b

This reply code revision is a modification of the protocol in

described in RFC 542, that is to say that the protocol

implementation associated with socket number 21 (decimal) is the

protocol specified by the combination of RFC 542 and this RFC. 5

A note of thanks to those who contributed to this work: Ken

Pogran, Mark Krilanovich, Wayne Hathway, and especially Nancy

Neigus. 6

NWG/RFC# 640 JBP NJN 5-JUN-74 16:07 30843

Nancy Neigus

Ken Pogran

Jon Postel

19 JUN 75

A New Schema for FTP Reply Codes 7

Replies to File Transfer Protocol commands were devised to ensure

the synchronization of requests and actions in the process of

file transfer, and to guarantee that the user process always

knows the state of the Server. Every command must generate at

least one reply, although there may be more than one; in the

latter case, the m...