RFC 62 (rfc62) - Page 1 of 20

Systems for Interprocess Communication in a Resource Sharing Computer Network

Network Working Group                                       D. C. Walden
Request for Comments: 62                                        BBN Inc.
Supercedes NWG/RFC #61                                     3 August 1970


                A System for Interprocess Communication
                                 in a
                   Resource Sharing Computer Network

1.  Introduction

   If you are working to develop methods of communications within a
   computer network, you can engage in one of two activities.  You can
   work with others, actually constructing a computer network, being
   influenced, perhaps influencing your colleagues.  Or you can
   construct an intellectual position of how things should be done in an
   ideal network, one better than the one you are helping to construct,
   and then present this position for the designers of future networks
   to study.  The author has spent the past two years engaged in the
   first activity.  This paper results from recent engagement in the
   second activity.

   "A resource sharing computer network is defined to be a set of
   autonomous, independent computer systems, interconnected so as to
   permit each computer system to utilize all of the resources of the
   other computer systems much as it would normally call a subroutine."
   This definition of a network and the desirability of such a network
   is expounded upon by Roberts and Wessler in [9].

   The actual act of resource sharing can be performed in two ways:  in
   an ad hoc manner between all pairs of computer systems in the
   network; or according to a systematic network-wide standard.  This
   paper develops one possible network-wide system for resource sharing.

   I believe it is natural to think of resources as being associated
   with processes and available only through communication with these
   processes.  Therefore, I view the fundamental problem of resource
   sharing to be the problem of interprocess communication.  I also
   share with Carr, Crocker, and Cerf [2] the view that interprocess
   communication over a network is a subcase of general interprocess
   communication in a multi-programmed environment.

   These views have led me to perform a two-part study.  First, a set of
   operations enabling interprocess communication within a single time-
   sharing system is constructed.  This set of operations eschews many
   of the interprocess communications techniques currently in use within
   time-sharing systems -- such as communication through shared memory
   -- and relies instead on techniques that can be easily generalized to



Walden