We consider a broadband network using the asynchronous transfer mode (ATM): several models have been investigated to study the expected performances for some available bit rates and some sizes of the network buffers. In a previous work (Pellaumail et al., Reseaux ATM et P-simulation, Hermes, Paris, 1994) some processes whose role is essential in several models were introduced. The aim of this paper is to give more information on these basic processes: explicit values of the stationary law, computing the moments, busy period, worst case law, etc.