In this paper, we present a predictive strategy for teleoperating through communication channels with unknown and possibly unbounded time delay, a remotely located precompensated plant subject to input and state-related pointwise-in-time constraints. The significance of the method is that it is capable of generating command signals such that, once received and applied to the remote plant, stability is preserved and no constraints violation occurs regardless of any possible time delay. The method can be further specialized to deal either with bounded time delay, as typically encountered in space and underwater applications, or with random and possibly unbounded roundtrip time delay, as in the Internet case. In order to demonstrate its effectiveness, a master/slave teleoperation problem over the Internet is considered. It consists of stabilizing via teleoperation a cart/rod inverted pendulum under cart motor voltage and rod angle constraints, through a communication link affected by time delay.