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RFC 432 UNKNOWN HISTORY · NETWORK

Network logical map

A snapshot of the ARPANET's physical connections in late 1972.

On rfc-editor.org ↗
PUBLISHED
December 1972
AUTHORS
N. Neigus
STREAM
Legacy
MAP DATE
December 30, 1972
PAGES
1
DOI
10.17487/RFC0432

RFC text

Original text · RFC Editor View on rfc-editor.org ↗

This text was converted from the RFC Editor's PDF edition and may contain conversion errors; the layout is approximate. The PDF is the reference copy.

Network Working Group                                          N. Neigus
Request for Comment: 432                                         BBN-NET
NIC: 13490                                                 December 1972


                           Network Logical Map

  Attached is the logical map of the network as of December 30, 1972.
  The ovals indicate the host computers that we think are connected to
  each IMP, with the double oval implying an interface. If there are
  any errors in the map or if your status vis-a-vis connected hosts, is
  going to change within the next few months, please contact:


            Nancy J. Neigus

            Bolt Beranek and Newman Inc.
            50 Moulton Street

            Cambridge, Ma. 02138

            617-491-1850      X511

  or leave a message for NJN at the NIC. In the future we would
  appreciate being notified any time there is such a change.


  NJN/jm

  Attach.


Attached is a figure of the ARPA NETWORK, LOGICAL MAP, JANUARY 1973


          [This RFC was put into machine readable form for entry]
      [into the online RFC archives by Helene Morin, Via Genie 12/99]

AI ELI5

On this page
PROBLEMEarly ARPANET researchers needed to know which computers were physically connected to which network interface machines (IMPs) at each site.
MECHANISMBBN published a logical map showing the network topology as of December 1972, with ovals representing host computers connected to each IMP, and requested that sites report any errors or planned changes.
HISTORICAL SNAPSHOTThe map served as a reference for understanding the ARPANET's structure at that time and coordinating further growth.

§1The ARPANET Map

RFC 432 is a short cover note from Bolt Beranek and Newman (BBN), the organization managing the early ARPANET, announcing a logical map of the network as of December 30, 1972. The ovals in the map indicate the host computers connected to each IMP (Interface Message Processor, the network's routing devices). Double ovals represent connections through an interface.

A short letter introducing a drawing of the network, showing which computers were connected where.

§2Purpose and Coordination

The RFC requests that recipients review the map for accuracy and notify BBN of any errors in the network topology or planned changes to their site's connections in the coming months. Contact information is provided for Nancy Neigus at BBN's Cambridge office, including a telephone extension and instructions to leave messages at the NIC (Network Information Center).

This coordination mechanism was essential for the early ARPANET, where changes to the physical network required careful tracking and notification across all participating sites.

BBN asked everyone to check the map and call if something was wrong or if they were adding more computers.

§3A Moment in ARPANET History

This RFC captures the ARPANET's state in the early 1970s, when the network was still relatively small and the complete topology could fit on a single map. As the network grew, such centralized maps became impractical and more sophisticated network management and discovery mechanisms developed.

This map shows the network when it was still small enough to draw on one page.