Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Some thoughts on file transfer (RFC0250)

IP.com Disclosure Number: IPCOM000003082D
Original Publication Date: 1971-Oct-07
Included in the Prior Art Database: 2000-Sep-13
Document File: 1 page(s) / 2K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

H. Brodie: AUTHOR

Abstract

There are several aspects of the proposed Data Transfer Protocol (RFC #171) and File Transfer Protocol (RFC #172) which we believe could use further clarification and perhaps revision. Interest in transferring larger amounts of data than is typically sent via the usual TELNET connection is increasing, and at least at UCLA-NMC implementation attempts have pointed out several difficulties with the proposed protocols.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 100% of the total text.

Network Working Group H. Brodie

Request for Comments #250 UCLA-NMC

NIC #7691 Computer Science

Categories: D5, D7 7 October 71

Updates: None

Obsoletes: None

Some Thoughts on File Transfer

There are several aspects of the proposed Data Transfer Protocol (RFC

#171) and File Transfer Protocol (RFC #172) which we believe could

use further clarification and perhaps revision. Interest in

transferring larger amounts of data than is typically sent via the

usual TELNET connection is increasing, and at least at UCLA-NMC

implementation attempts have pointed out several difficulties with

the proposed protocols.

First, and probably most easily decided, is the ambiguity in RFC #171

with regards to the sequence number field of the descriptor and count

transaction. The description provided for the transaction header

provides for 16 bit sequence number. However, the sequence number

field in the error codes transaction only provides for 8 bits. We

are of the opinion that 8 bits is sufficient for a sequence number

field. If the sequence number is reduced to 8 bits, and the two NUL

bytes are deleted from the descriptor and count header, then its size

is reduced to 48 bits, which would seem to be as convenient to handle

as the proposed 72 bit transaction header.

Another source of difficulty lies in the implementation of the (the

SEX time-sharing system) the 'end' of a file (which presumably would

be the begin point of an Append transaction) is almost com- pletely

context-defined--i.e., the program reading the file determines when

it has reached the end of the file. Therefore, the meaning of

'Append' is somewhat hazy, and since the proposed Mail Box Protocol

uses the Append feature, not implementing this command in a File

Transfer service is costly in terms of lost useability.

We believe that resolution of these ambiguities will lead to a

greatly accelerated implementation schedule, at least here at UCLA-

NMC.

[ This RFC was put into machine readable form for entry ]

[ into the online RFC archives by BBN Corp. under the ]

[ direction of Alex McKenzie. 12/96 ]