A robust controller is derived for networked control systems with uncertain plant dynamics. The link between the nodes is disturbed by time-varying communication delays, samplings and time-synchronization. A stability criterion for a robust control is presented in terms of LMIs based on Lyapunov-Krasovskii techniques. A second-order system example is considered and the relation between the admissive bounds of the synchronization error and the size of the uncertainties is computed.