A survey of the NARSIM C/S middleware

A survey of the NARSIM C/S middleware

Michiels, R.W.F.J.

National Aerospace Laboratory NLR

1996-05-31

This document describes the Client/Server system architecture of NARSIM - the NLR Air Traffic control Research Simulator- focussing on the socalled middleware: the infrastructure that enables all the seperate parts of the simulator to interact with each other. To show the full scope of the architecture, first a somewhat abstract architecture description is given, followed by more concrete technical implications of this architecture and the particular implementation chosen within NARSIM. Also some non-technical issues are discussed which are direct results from either the architecture or the specific implementation. Finally in the appendices a survey of the NARSIM C/S servers is given together with other system documentation, to give a better understanding of the environment in which the NARSIM C/S middleware operates. The most distinctive feature of the NARSIM Client/Server architecture is probably the perfect symmetry between clients and servers. An application cannot be labeled statically as either server or client: only with respect to a certain dialogue can one application be a labeled as a server and the other as a client. Initial experience with the new architecture has shown that this perhaps seemingly arbitrary view of clients and servers has some profound positive consequences on the architecture as a whole, such as a very low degree of complexity and thus ease of understanding and maintenance.

air traffic control
applications programs (computers)
architecture (computers)
client server systems
computer systems design
distributed processing
interprocessor communication
modularity
protocol (computers)
simulators
Unix (operating system)

http://resolver.tudelft.nl/uuid:3adbd868-bb81-4cf7-bff5-474efe9cd857

Campus only

NLR Technical Publication TP 96220 U

Aerospace Engineering Reports

report

(c) 1996 National Aerospace Laboratory NLR