Browse Prior Art Database

Proposed Change in IMP-to-Host Protocol (RFC0312) Disclosure Number: IPCOM000003508D
Original Publication Date: 1972-Mar-01
Included in the Prior Art Database: 2019-Feb-12
Document File: 2 page(s) / 3K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

A.M. McKenzie: AUTHOR

Related Documents

10.17487/RFC0312: DOI

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 65% of the total text.

Network Working Group A. McKenzie RFC #312 BBN NIC 9342 22 March 1972 Categories: B.1

Proposed Change in IMP-to-Host Protocol

We are currently considering a redefinition of the IMP-to-Host error message types (type 1 and type 8) and the creation of addi- tional IMP-to-Host error message types. We believe that these changes will assist the Hosts in determining appropriate recovery action, without causing any serious reprogramming problems. Our current plans are to install these changes within a few months; therefore we should be informed of any strong negative reactions relatively quickly.

The proposed changes fall into two general classes as de- scribed below:

A) General Error Message ---------------------

Under certain circumstances, particularly when the Host has been unresponsive to queued input for a "long time" the IMP drops its ready line for a short period, causing the "error flip-flops" to be set (see RFC #270, NIC 7818). Under these conditions the IMP sends a few NOP’s to the Host and then resumes normal operation. We propose to send the Host a new message (message type 13) in addition to the NOPs; this message will tell the Host that the IMP’s Ready Line was dropped, that the IMP’s error flop was set, and that the IMP will respond to the next com- pletion of a Host-to-IMP message with a type 1 or type 8 message (because of the setting of the IMP’s error flop.

B) Error Messages which are Responses to Specific ---------------------------------------------- Host-to-IMP Transmissions: --------------------------

1) IMP-to-Host message type 1 will be redefined to mean: "IMP’s Error flip-flop was set on a message which the IMP cannot identify."

2) IMP-to-Host message type 8 will be redefined to mean: "IMP’s Error flip-flop was set during receipt of the message identified...