RFC 33 (rfc33) - Page 2 of 19

New Host-Host Protocol

RFC 33                   New HOST-HOST Protocol         12 February 1970


   machines and operating systems involved in the network vary widely.
   For example, the computers at the first four sites are an XDS 940
   (Stanford Research Institute), an IBM 360/75 (University of
   California, Santa Barbara), an XDS SIGMA-7 (University of California,
   Los Angeles), and a DEC PDP-10 (University of Utah).  The only
   commonality among the network membership is the use of highly
   interactive time-sharing systems; but, of course, these are all
   different in external appearance and implementation.  Furthermore, no
   one node is in control of the network.  This has insured reliability
   but complicates the software.

   Of the networks which have reached the operational phase and been
   reported in the literature, none have involved the variety of
   computers and operating systems found in the ARPA network.  For
   example, the Carnegie-Mellon, Princeton, IBM network consists of
   360/67's with identical software. [2]  Load sharing among identical
   batch machines was commonplace at North American Rockwell Corporation
   in the early 1960's.  Therefore, the implementers of the present
   network have been only slightly influenced by earlier network
   attempts.

   However, early time-sharing studies at the University of California
   at Berkeley, MIT, Lincoln Laboratory, and System Development
   Corporation (all ARPAA sponsored) have had considerable influence on
   the design of the network.  In some sense, the ARPA network of time-
   shared computers is a natural extension of earlier time-sharing
   concepts.

   The network is seen as a set of data entry and exit points into which
   individual computers insert messages destined for another (or the
   same) computer, and from which such messages emerge.  The format of
   such messages and the operation of the network was specified by the
   network contractor (BB&N) and it became the responsibility of
   representatives of the various computer sites to impose such
   additional constraints and provide such protocol as necessary for
   users at one site to use resources at foreign sites.  This paper
   details the decisions that have been made and the considerations
   behind these decisions.

   Several people deserve acknowledgement in this effort.  J. Rulifson
   and W. Duvall of SRI participated in the early design effort of the
   protocol and in the discussions of NIL.  G. Deloche of Thompson-CSF
   participated in the design effort while he was at UCLA and provided
   considerable documentation.  J. Curry of Utah and P. Rovner of
   Lincoln Laboratory reviewed the early design and NIL.  W. Crowther of
   Bolt, Beranek and Newman, contributed the idea of a virtual net.  The
   BB&N staff provided substantial assistance and guidance while
   delivering the network.



Crocker, et. al.