Proposed Change to Host/IMP Spec to Eliminate Marking
A proposal to send the Host/IMP leader and message text separately to avoid marking problems.
Crowther, W.R., "Proposed Change to Host/IMP Spec to Eliminate Marking", RFC 67, DOI 10.17487/RFC0067, January 1970, <https://www.rfc-editor.org/info/rfc67>.
@misc{rfc67,
series = {Request for Comments},
number = 67,
howpublished = {RFC 67},
publisher = {RFC Editor},
doi = {10.17487/RFC0067},
url = {https://www.rfc-editor.org/info/rfc67},
author = {W.R. Crowther},
title = {{Proposed Change to Host/IMP Spec to Eliminate Marking}},
pagetotal = 1,
year = 1970,
month = jan,
} RFC text
Network Working Group W. Crowther
Request for Comments #67 BBN
[IMPORTANT]
Proposed Change to Host/IMP Spec to Eliminate Marking
Before he left for Norway, Dave Walden observed that there was a
simple change to the Host/IMP specifications which would eliminate all
"marking" problems. The change is to separate the leader from the text
of regular messages, and then to send them as consecutive messages
instead of one packed message. The text would then start on a word
boundary no matter what the word lengths of the machines involved. The
process would take place on both IMP-to-Host and Host-to-IMP messages.
We can see no disadvantages to this scheme, and a sampling of Host
reactions range from neutral to wildly enthusiastic. Therefore, we
tentatively plan to implement this change. We recognize that this
change will involve Host program changes, and that the new release must
be scheduled to coincide with those changes. We propose providing
modified Host spec text along with a one week notice of the new release.
If anyone sees a flaw in this scheme, or is unhappy about it, please
contact BBN quickly, since a new version of the IMP program is already
in the works.
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by Kai Henningsen 5/97 ]
ISO Plain Language
On this page
§1The Marking Problem
W. Crowther reports a suggestion from Dave Walden: change the Host/IMP specifications to eliminate marking problems. The note says the packed leader and text caused the issue, but it does not define the marking problem in more detail.
The proposed goal is for message text to begin on a word boundary regardless of the word lengths used by the machines involved.
The note says packed message parts caused marking problems across machines. It aims to make the text start at a word boundary on every host.
§2Separate the Leader from the Text
Instead of packing the leader and text in one message, send the leader and text as two consecutive messages. The text would then start on a word boundary.
The proposed change applies to both IMP-to-Host and Host-to-IMP messages.
Send the message information first and the text second. This separates the two parts in both directions.
§3Tentative Implementation Plan
The authors see no disadvantages, and a sample of Host reactions ranges from neutral to very enthusiastic. BBN therefore tentatively plans to implement the change.
Because Host programs must also change, BBN proposes coordinating the new IMP release with those program changes and supplying updated Host specification text with one week's notice. It asks people to report objections quickly because a new IMP program version is already in progress.
BBN tentatively plans to make the change, but Host programs must change too. BBN proposes giving one week's notice before the new release.