DPN (Data Packet Networks) Expert Advisor was a research project at the Bell-Northern Research laboratories [1]. It proved to be a very efficient technique for detecting network problems out of a stream of massive number of alarms coming from DPN data switches [2].

The knowledge base supporting that model consisted of a number of problem descriptions. The problem scripts were written in a language called the Problem Description Language that was designed for the project. The language had an easy to use, English-like syntax, as it was directed towards the network operators that usually lacked higher level of education and did not know anything about programming computers.

The users modified or created problem scripts with the help of a customization tool [3]. These files were compiled into the record structures used by the expert system. The knowledge base could be altered on-line, without interrupting the monitoring of the network. It implied that the expert system could work with many knowledge bases and switch from one to another on-line. Additionally, the modularity of the knowledge base allowed the system administrator to alter only selected parts of the active knowledge base.


  1. White T., Bieszczad A. (1992), The Expert Advisor: An Expert System for Real Time Network Monitoring. European Conference on Artificial Intelligence, Workshop on Advances in Real Time Expert System Technology.
  2. Sue Abu-Hakima (with Bieszczad, A. and White, T. contributions) (1994), The DPN Expert Advisor: Canadian AI Success Story #3, Canadian Artificial Intelligence, No. 33.
  3. Bieszczad, A., White, T. (1992), Customization of network surveillance expert systems. Proceedings of GLOBCOM’92, Vol. 2, pp. 1250-1255, December 1992, Orlando, FL.