Overview of the BNU processes

Most tasks associated with Basic Networking Utilities administration may be performed using either the menu system or shell commands entered on the command line.

There follows a general description of the BNU process. The phases are marked on the diagram that follows.

Phase A

A user on the local machine issues a command requesting file transfer or remote execution communication with a remote computer (phase A). Several BNU database support files are read to determine if the remote computer is accessible by the local computer and the priority of the user's request compared to other users' requests. This phase ends by queuing the user's request in a spool area on the local machine and triggering the next phase.

Phase B

The uucico routine is triggered automatically (phase B). It reads several BNU database support files to determine when the remote computer can be reached, how to establish the link to the remote computer, how to handle data flow between the local and remote computers, and the maximum number of simultaneous requests for communication to the remote computer.

Phase B'

The uucico routine calls the connection routine, dials(3N), and passes the request and associated information to the server.

Phases C and C'

The uucico routine on the remote computer is triggered automatically when a call for communication is received from the local computer (phase C). In this phase, the remote uucico routine reads BNU database support files on its computer to determine if the calling computer is allowed access, and what action to take if the calling computer is not allowed access (phase C'). For calling computers that are allowed access to the remote computer, the level of access is determined in this phase.

Phase D

Requests initiated on the local computer may contain commands to be executed on the remote computer (phase D). When these commands arrive on the remote computer, they are stored in a spool area. During this phase, the remote uuxqt routine runs these commands on the remote computer.

Basic networking process diagram