Specifications for Network Use of the UCSB On-Line System
RFC 74

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions

Network Working Group                                           J. White
Request for Comments: 74                                            UCSB
                                                        October 16, 1970

       SPECIFICATIONS FOR NETWORK USE OF THE UCSB ON-LINE SYSTEM

Introduction

   UCSB's On-Line System (OLS) is available to Network users as socket
   number x'101' at site 3.  Network users should log in with the
   following OLS accounts parameters:

           USER NUMBER = 196
           ID NUMBER =  57372
           USER NAME = site name -- UCLA, SRI, UTAH, BBN, MIT, SDC, RAND
                       -- whichever is appropriate

   Users communicate with OLS through an intermediary process, hereafter
   called the Interface, which is addressed as socket number x'101'
   (which is termed OLS's "primary socket"), and can be invoked through
   the Logger.  This document is intended to provide programmers with
   the information necessary to communicate with the Interface; and to
   define the input expected and the output returned.  The readers is
   assumed familiar with the Culler-Fried system at UCSB from a user's
   standpoint.  Specifically, this document is not a user's manual for
   OLS.

   The interface conducts all Network transactions through the NCP,
   which operates under the Host-Host protocol of 3 August 70.  The
   first message sent by the Interface is of Type 0: the first eight
   bits are zeros and thereafter, for the life of the connection Imp-
   message boundaries are not significant.  Similarly, the Interface
   expects the first message it receives to be Type 0, discards the
   first eight bits assuming them to be zeros, and thereafter for the
   life of the connection takes no notice of Imp-message boundaries.

   A word about terminology.  The 360/75 is a 32-bit machine, but its
   instruction set is byte-oriented.  A byte is eight bits, and those
   eight bits are numbered 0-7 from left to right.  Terms such as

   "listen", "request connection", "accept a connection", and "reject a
   connection" are used freely herein to describe those primitive
   Network functions, which are user at a foreign site presumably has
   available to him through his NCP.  They are used here in the same
   senses in which they have frequently been used in the NWG literature.

White                                                           [Page 1]
RFC 74             Network Use of UCSB On-Line System   October 16, 1970

Logging Into the Interface

   To use the On-Line system, the Network user must establish a full-
   duplex connection with the Interface.  The Interface is core resident
   only while at least one such duplex connection is established (i.e.,
   while at least one Network user is connected).  At all other times,
   the Interface resides on direct-access storage and must be invoked
   through the Logger.  A login sequence can always be initiated by
   requesting connection to OLS's primary socket.  While in core, the
   interface listens on that socket and will accept any call it
   receives; at all other times, the _Logger_ listens on that socket and
   will _reject_ the first call it receives, read the Interface into
   core, and dispatch it.  The Interface will then listen on the primary
   socket as before.  Thus, to initiate a login sequence, the user
   requests connection to the primary socket.  If accepted, he is in
   contact with the Interface.  If rejected, he should reissue the
   connection request; when accepted, he will be connected to the
   Interface.  A second rejection would indicate that the On-Line System
   was inactive, or that either the Interface or the NCP had exhausted
   its resources.

   Over this initial connection, the Interface will send eight bits of
   zeros, indicating message type zero, followed by a 32-bit socket
   number, which it will select from a pool of socket numbers allocated
   to it.  It will then promptly close the connection and reissue the
   listen, to allow other users to begin login.  It will then request
   connection of the local socket whose number was sent to the user,
   with the foreign socket whose number is one greater than that of the
   user's socket.  Similarly, it will request connection of the local
   socket whose number is one greater than that sent to other user, with
   the user's socket.  Once the two connections have been established,
   the Interface will consider the user logged in.

   The two connections thus established are maintained indefinitely by
   the Interface.  Over its receive connection (hereafter termed the
   "Input Connection"), the Interface accepts input fro OLS.  Over its
   send connection (the "Output Connection"), the Interface relays
   displays from OLS generated in response to the input.  The Interface
   will terminate the connections only should the On-Line System
   terminate.  The user is expected to close the two connections when
   finished, making the local sockets available for reallocation, at