UNISIM: a simulation program for communications networks

The design and analysis problems associated with large communications networks are frequently not solvable by analytic means and it is therefore necessary to turn to simulation techniques. Even with networks which are not particularly large the computational difficulties encountered when other than very restrictive and simple models are to be considered preclude analysis. It has become clear that the study of network characteristics and traffic handling procedures must progress beyond the half-dozen switching center problem to consider networks of dozens of nodes with hundreds or even thousands of trunks so that those features unique to these large networks can be determined and used in the design of communications systems. Here it is evident that simulation is the major study tool.