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RFC 395 UNKNOWN NETWORK OPERATIONS · HARDWARE

Switch Settings on IMPs and TIPs

Front-panel switch configuration for network routers

On rfc-editor.org ↗
PUBLISHED
October 1972
AUTHORS
J.M. McQuillan
STREAM
Legacy
IMP MODELS COVERED
516 and 316
516 CRITICAL SWITCHES
6 switches
316 CRITICAL SWITCHES
Sense switches 1-4
DOI
10.17487/RFC0395

RFC text

Original text · RFC Editor View on rfc-editor.org ↗ 
Network Working Group                     John M. McQuillan
RFC # 395                                 Bolt Beranek and Newman Inc.
NIC # 11587                               3 October 1972
Categories: Updates:
Obsoletes:

                    SWITCH SETTINGS ON IMPS AND TIPS
                    --------------------------------

This note provides a description of the switches on the front panel of
IMPs and TIPs that are important to the correct operation of the
network software.  We have had some difficulty in the past when
certain of these switches were set incorrectly, This RFC will be
updated as necessary, to notify site personnel of changes to the
settings.

A.  516 IMPs
    --------
The IMP at your site is a model 516 if it has a gray cabinet and two
rows of indicator lights on the front panel.  The correct switch
settings are:

     1.   Sense switches 1,2,3 and 4:  OFF (DOWN)
     2.   PFI/PFH:  PFI (UP)
     3.   HALT INH:  OFF (DOWN)
     4.   W.D.T.:  OFF (DOWN)
     5.   AUTO RSTRT:  ON (UP)
     6.   MEMORY PRTCT:  OFF (DOWN)

B.  316 IMPs and TIPs
    -----------------
The IMP at your site is a model 316 if it is a TIP or if it is in a
black cabinet and has one row of indicator lights on the front panel.

     1.  Sense switches 1,2,3,4 OFF  (top half depressed)

Site personnel are requested to keep a copy of this RFC near the IMP
and to check the switch settings at their IMP.  In addition, the
Honeywell field engineers who perform preventive maintenance have been
requested to use this note as a checklist.


       [ This RFC was put into machine readable form for entry ]
       [ into the online RFC archives by BBN Corp. under the   ]
       [ direction of Alex McKenzie.                      1/97 ]

AI ELI5

On this page
PROBLEMIncorrect front-panel switch settings on IMPs and TIPs had caused network problems, and there was no documented checklist of correct settings.
MECHANISMThis RFC publishes a simple list of which switches must be ON or OFF for the two main IMP models (516 and 316) to operate correctly.
PRACTICAL IMPACTThe checklist became standard operational guidance, to be kept at each site and used by field engineers during maintenance.

§1Switch Configuration Problem

Network sites had experienced problems because front-panel switches on IMPs (Interface Message Processors) and TIPs (Terminal Interface Processors) were set incorrectly. This RFC provides the correct settings as a checklist for site personnel and maintenance engineers to follow.

When switches are in the wrong position, the network machines stop working. This is the list of where every switch should be.

§2516 IMP Settings

The model 516 IMP has a gray cabinet with two rows of indicator lights on the front panel. The correct settings are: Sense switches 1, 2, 3 and 4 set OFF; PFI/PFH set to PFI; HALT INH set OFF; W.D.T. (Watchdog Timer) set OFF; AUTO RSTRT set ON; and MEMORY PRTCT set OFF.

For the big gray machine, most switches go down, but the restart switch goes up.

§3316 IMP and TIP Settings

The model 316 appears either as a TIP or in a black cabinet with one row of indicator lights. For this model, the only critical setting is Sense switches 1, 2, 3 and 4, all set to OFF (top half depressed). The RFC requests site personnel keep a copy nearby and advises field engineers to use it as a maintenance checklist.

For the smaller machine in the black box, just make sure the four sense switches are all pressed down.