Motivation

The conferencing facility available on most modern telephone exchanges is extremely useful. Many commercial analogue Video/Audio conferencing systems offer an analogous service. What characterizes these services is the lack of structure to the conference; a common complaint is that it is hard to work out which person on a screen is the new speaker. This paper outlines the design of a conferencing system for windowing workstations, and looks at some of the possibilities for powerful <#1176#> floor control mechanisms<#1176#> beyond the simple-minded (and probably un-manageable) multi-way version of talk. Talk is a simple minded program that divides the screen on a dumb terminal into two areas. What the user types appears in ``their'' half on their screen, and the ``other'' half on the other terminal. The users may type simultaneously, and the sequence of output will be interleaved almost arbitrarily on the other user's screen. The program is extended over the network so that users with terminals attached to different hosts may use the facility in a network transparent way (excepting delays). This is done using a reliable byte stream protocol appropriate for one to one communication. The system is limited to two parties.