Outline of Research

The Communications Group of the Faculty of Computer Science,
University of New Brunswick, Fredericton, NB, Canada is
currently involved in the development of a universal Protocol 
Simulation Testbed. Although commercially available software-
based protocol testbeds are available, they are generally 
oriented to network evaluation and planning and lack the 
flexibility required for use as a research tool for protocol 
design, testing and verification.

	Participating in this research and development work are 
(in alphabetical order) Dr. Aziz Al-Zoman (formerly Ph.D. student), 
John M. Dedourek (Professor), Dr. Bernd J. Kurz (Professor) and 
Adam Reece (MCS student). 

	During the past few years we have developed a software-
based simulation testbed to simulate the 7-layer OSI protocol
stack for (currently) point-to-point communication and
evaluate the performance of protocol suites. This is a very
flexible and modularized model which allows quick exchange
of protocol layers (testing what-if scenarios), traffic
loads generated by statistical or deterministic generators
(with data from measured sessions), and the definition of
digital channel media with many error types injected by
statistical error generators (statistical models or from
measured data), such as for cellular telephone and satellite
channels.

	The testbed software is written in C with the simulation 
library package SMPL, and runs under AIX on a RS6000 work 
station.
	


	Currently available protocol layers are HDLC in
many versions, including our own enhanced HDLC version, as
well as channel models for cellular telephone links. Also 
available is ATM with a newly-developed AAL5 interface to HDLC, 
and a Satcom channel model for upcoming research work.

	Recent research work carried out on the Protocol 
Simulation Testbed deals with the development of a robust 
HDLC protocol for harsh error environments, and for the 
evaluation of ATM over Satellite


A New Face for our Protocol Testbed
The Protocol Testbed was developed as a versatile research tool. 
As such it requires a code manipulation and recompilation process 
every time the protocol stacks are changed. Although this code 
manipulation is made easy due to the modular design of the testbed 
software, amounting essentially to shifting out a previous protocol 
layer software module and shifting in a new one, this was nevertheless 
a time-consuming and error-prone process.

     Currently, work is in progress to develop and design a graphical 
front end to the testbed which allows a user-friendly configuration of 
the protocol stacks. Using drag-and-drop methods, (sub)protocols can be 
selected from a pool of available (sub)protocol modules and moved into the 
protocol stacks at both ends of the simulated point-to-point 
communication  system. Certain protocol configuration parameters can 
also be specified at this time. The GUI front-end interchanges its 
configuration specification with the existing testbed via a configuration 
file, which in turn, contains hooks into the testbed's internal software 
structure. The Protocol Testbed will be started from the graphical front 
end and automatically configure itself as specified prior to running a 
simulation session.

     The addition of this GUI configuartion front-end will make the 
Protocol Testbed more readily usable in repetitve 'what-if' scenarios, 
and will help speed up our research on protocol design and performance 
evaluation considerably. 

     We have chosen Java (with GUI builder) as the language of 
implementation for the testbed's GUI. This will allow us to operate the 
testbed from our local workstations, and also ultimately make the 
testbed available to remote operators via the WWW. This is our first 
step to establishing a telepresence of our laboratory equipment for 
research telework.

    This work is carried out jointly by Dr. Bernd J. Kurz (Professor), 
John M. Dedourek (Professor) with the assistance of Bruce Ashfield and 
Poorang Irani, undergraduate Honors students.

Project Status: Started:   November 1991
                Completed: Testbed April 1995,
                           GUI Front End April 1997,

Relevant Publications

Ashfield, Irani: A Graphics Shell for a Protocol Simulation 
  Testbed, CS4997 Honors Thesis, Fac. of Computer Science, 
  Univ. of New Brunswick, April 1997, 102 pages

Back to: Kurz's Research Page | Kurz's Home Page

Last revised: 6 June 1997 by Bernd Kurz bjkurz@unb.ca