Over The Shoulder: Real-Time Collaboration Over High Speed Networks

Michael T. Swink, Joseph B. Evans, Victor S. Frost

Telecommunications & Information Sciences Laboratory
Department of Electrical Engineering & Computer Science
University of Kansas
Lawrence, KS 66045-2228


This talk covers the design and implementation of the Over The Shoulder (OTS) real time screen viewing and control application. This application allows users to not only look at the display of a remote X-Windows based workstation, but it also allows for full remote control of the machine being viewed. Using this application, a remote instructor, for example, might aid a student in the use of a WWW browser or CAD program. OTS allows the remote user to view the student's workstation screen, pull down menus, click on buttons, and in general perform any action which the local user might perform. In addition to the above features, OTS is also capable of sending the images that it is viewing to a large number of remote displays via IP multicast.

OTS was created as a sample high bandwidth collaborative application for exercising ATM-based networks. Due to this fact, OTS has the ability to collect and store detailed information about its network I/O performance. This feature was used to conduct several tests of the MAGIC wide area ATM/SONET network with various ATM switches and network loads. The results of these tests have helped to identify many of the strengths and weaknesses of current networks. Data rates ranging from approximately 1 Mb/s up to 34 Mb/s have been measured, based on the frame update rates selected by the user.

The OTS application is being deployed in the multimedia classroom facilities in three buildings separated by several kilometers on the University of Kansas campus. These teaching facilities are linked by a 622 Mb/s ATM/SONET infrastructure. It is anticipated that the aggregate traffic generated by use of the OTS tool by groups of instructors and students will stress this network and provide further insight into the design of broadband networks.

Title Page, Contents