Performance analysis of the D channel access control scheme in the ISDN basic user/network interface

In the basic user/network interface of ISDN (ITU-T Recommendation I.430) th e D-channel is shared by up to 8 terminals for signal and data packets. An analytical model is proposed to reveal the performance characteristics of t he access control scheme for the D-channel. Numerical and simulation result s are shown to demonstrate the performance differentiation of the terminals with different priorities. It is observed that the mean signal delay at lo w load may become large because of long service time for packets, and that the priority mechanism may not work properly when the loads at terminals ar e very asymmetric.