Department of Computer and Systems Sciences
Stockholm University and KTH.

Part 2: Computer Conferencing standards

February 1992

Last update: 3 August 1996 by Jacob Palme E-mail: jpalme@dsv.su.se.

With increasing use of electronic mail and computer conferencing, people will more and more often be required to participate in conferences in different installations with different software. And most people are not willing to go to the trouble of connecting to several different conference systems. This is especially true if they also will have to learn different user interfaces to different shades of functions.

This problem can be solved by standards.

Figure 2: Group Communication Architectural Model

In order to understand the alternative options for writing standards, the model shown in figure 2 can be used. In this model, each user is connected to a User Agent or Group Communication User Agent (GCUA) which handles the interaction with that user, and maybe also a personal data base of messages for that user [1].

Each GCUA is connected to a multi-user server, called GCSA (Group Communication Service Agent) in figure 2. The GCSA can communicate with other GCSA-s.

The digit "1" in the figure represents the interface between the user and the conference system, as shown on the user screen.

Many modern conferencing systems have a software component which runs locally in the personal computer or workstation of the user. The digit "2" in the figure represents the communication between such a software component and a server. This means that for some conference systems, no such interface "2" exists.

The digit "3" in the figure represents the communication between two conference systems, of the same or different type.

A standard for computer conferencing could standardize any of these three interfaces, numbered 1, 2 and 3 in the figure.

Standardizing the interface 1 would thus mean that the words and commands used in the actual user interface is standardized. The disadvantage with such standards is that they hinder future development of new and better user interfaces. Because of this, standards organizations usually avoid standardizing this interface.

Standardizing the interface 2 would mean that the user can buy one piece of UA software, with one type of user interaction. This UA software could then connect to several different conference systems, but the user would still have the same user interface. The disadvantage with standardizing 2 is that all conference systems do not use such personal computer software, and that different systems divide the task between the GCUA and the GCSA in different ways.

Standardizing the interface 3 would mean to provide a standardized way of different conference systems to communicate with each other. All existing standards mainly standardize this interface.

The following standards exist today:

The Internet mail standards [3], [17]. These are mainly standards for inter-personal mail. They are widely used, but have very limited functionality.

The ISO/CCITT X.400/MOTIS standards [2]. These have much more functionality than the Internet mail standards, especially in the areas of notifications, body types and distribution lists.

The Usenet News standards [6]. This is a rather limited standard for the exchange of information between GCSA-s.

ISO and CCITT are working on the development of new standards. These may be ready in a first version in about 1995.

ISO/CCITT standards are based on the Open Systems Interconnection model [7]. This model provides basic facilities for the interconnection of systems. The Remote Operations Service (ROS, [10]) uses OSI to make it easy to develop new protocols. A special language, Abstract Syntax Notation 1 (ASN.1, [9]) is used to define the format of the data structures exchanged between systems in a computer-type-independent way.

The forthcoming ISO/CCITT standards are going to define an architecture, i.e. a description of the different types of nodes (like GCUA-s and GCSA-s) which can connect.

They will then define a common information model, a view of the data base organization in group communication systems. They will define the user functionality in what is called an Abstract Service Description.

They will then define the operations in the protocols to be defined, like the protocol between a GCUA and a GCSA (2 in the figure) and the protocol between a GCSA and another GCSA (3 in the figure).

The forthcoming ISO/CCITT standard will contain a basic general group communication model, and define applications based on this general model. Example of such applications are basic computer conferencing, voting, joint editing, distance education, office procedures etc.

The other parts.

References:

[1] Benford, S. and Palme, J.: Developing Standards for OSI Group Communication. Not yet accepted for publication.

[2] CCITT, Message Handling Systems: System Model - Service Elements, Recommendation X.400, 1988, (Also published as ISO International Standard 10021).

[3] Crocker, D.H.: Standard for the Format of Arpa Internet Text Messages. August 1982. Network Information Center RFC822, SRI, California, 1982.

[4] Hiltz, S.R., Johnson, K., Aronovitch, C. and Turoff, M.: Face-to face vs. computerized conferencing: A Controlled experiment, New Jersey Institute of Technology, Newark, Research Report no 12.

[5] Hiltz, S.R. and Turoff, M.: Structuring Computer-mediated Communication Systems to avoid Information Overload. Communications of the ACM, July 1985, pp 680-689.

[6] Horton M.R., Adams R., Standard for the Interchange of USENET Messages, Network Information Center RFC 1036, SRI, California, 1987.

[7] International Organisation for Standardisation - Basic Reference Model for Open Systems Interconnection, ISO 7498, 1984.

[8] International Standards Organization: Group Communication functionality. ISO/IEC JTC 1/SC 18/WG 4 document N1144, January 1990.

[9] International Organisation for Standardisation - Information Processing Systems - Open Systems Interconnection - Specification of Abstract Syntax Notation One (ASN.1), ISO 8824, 1986.

[10] International Organisation for Standardisation - Information Processing Systems - Text communication - Remote operations (ROS), ISO 9072, 1988.

[11] Keehan, Michael T.: The Participate computer conferencing system. AFIPS Office Automation Conference, Los Angeles, February 1984.

[12] Palme, J: Cost-Benefit Analysis of Computer-Mediated Message Systems. In Information Processing 86, Proceedings of the World Computer Conference 1986 pp 1021-1023.

[13] Palme, J.: Experience with the use of the COM computer conference System. QZ UniversitetsData AB report C10166E, 1982, 1984.

[14] Palme, J. and Tholerus, T.: SuperKOM - Design considerations for a distributed, highly structured computer conferencing system. In Computer Communications, vol. 15, no. 8, october 1992 pp 509-518.

[15] Palme, J.: SuperKOM - a distributed computer conference system. Proceedings of the IFIP Symposium on Message Handling Systems and Application Layer Communication Protocols, Zürich, October 1990, North-Holland.

[16] Palme, J.: Data Base Structure in PortaCOM. Byte Magazine, December 1985.

[17] Postel, J.B.: Simple Mail Transfer Protocol. Network Information Center RFC821, SRI, California, 1982.

[18] Turoff, M.: Computer-mediated Communication requirements for group support. Journal of organizational computing, volume 1, number 1, 85-113, 1991.

[19] Vallee, Jaques: The Forum project - network conferencing and its future applications. Computer Networks, 1(1976) pp 39-52.

[20] Whitescarver, J. et al., A Network Environment for Computer Supported Cooperative Work, Proceedings of the ACM SIGCOMM `87 Workshop: Frontiers in Computer Communications Technology, ACM Press, 1988, 230-244.