Browse Prior Art Database

Proposed Change in IMP-to-Host Protocol (RFC0312)

IP.com Disclosure Number: IPCOM000003508D
Original Publication Date: 1972-Mar-22
Included in the Prior Art Database: 2000-Sep-13
Document File: 2 page(s) / 3K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

A.M. McKenzie: AUTHOR

Abstract

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.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 80% 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

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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

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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 by the 'source' and 'link number'

bits of this error message."

3) IMP-to-Host message type 10 will be defined to mean:

"A Host-to-IMP message was too short (and cannot be

identified)."

4) IMP-to-Host message type 11 will be defined to mean:

"A Host-to-IMP message was too long; the message is

iden...