The master-slave synchronization problem for two cart-pendulum systems when both measurement and control signals are transmitted via intranet communication channel is examined. The speed-gradient method for exciting master system and linear state feedback for slave system is used. Theoretical analysis is performed by the nonlinear extension of Fridman’s method. Experimental results are presented for a cart-pendulum system constructed from Lego. Theoretical bound for sampling interval guaranteeing synchronization is about h=0.1 sec. Such bounds are positive for control over intranet and very negative for control over internet. However experiments show that real values of the communication delays are even bigger.