Finding paths that satisfy the performance requirements of applications according to the link state information in a network is known as the quality-of-service (QoS) routing problem and has been extensively studied. However, distributing the link state information may introduce a significant protocol overhead on network resources. In this paper, based on rate-distortion analysis, we investigate the issue on how to update the link state information efficiently and effectively. A theoretical framework is presented, and a high performance link state policy that is capable of minimizing the false blocking probability of connections under a given update rate constraint is proposed. Through theoretical analysis and extensive simulations, we show that the proposed policy outperforms the current state of the art in terms of the update rate and false blocking probability of connections.