Dead Reckoning mechanism allows to reduce the network bandwidth utilization considerably. As available bandwith is the key problem for large DIS, we expect that a Dead Reckoning mechanism will allow to increase the number of entities involved in a DIS exercise.In this paper we model a Dead Reckoning mechanism and we present an evaluation of its performance. Such a mechanism reduces the number of PDU exchanged during the simulation. But it also completly changes the nature of the stochastic process which models the arrivals of PDUs. Indeed, it adds some kind of sporadicity. We present some measurements on a DIS simulator which exhibits such a behaviour. Then we investigate the effects of such a mechanim in terms of response time and number of allowed entities using a simulation tool. Some extensions towards the numerical resolution of a large Markov chain associated to the problem are finally presented.