Application of ATM network simulation to TMN studies

RACE project R2059 ICM is developing a cell rate ATM network simulator for aiding the development of a generic Telecommunications Management Network (TMN) testbed. This simulator provides a means to test the TMN system in a controlled environment before interfacing with a physical network. It provides network scaling, which is not possible on existing ATM networks, and also allows the control of more advanced facilities to be tested, e.g. advanced Connection Admission Control algorithms. This paper describes the rationale behind simulation work in an essentially network management based project such as ICM before going on to describe the design of the simulator itself. With the modular approach adopted for the simulator´s conceptual and functional architecture, the network model part of programs can be ported easily to different kinds of synchronisation mechanisms. The reasoning behind the choice of the cell rate approach as a model for the traffic flow in the network and the use of time-stepping to synchronise time across all the models is discussed. A Q adapter function can be used to `hide´ the fact that a simulator and not a real ATM network is connected to the TMN