The paper aims to analyse high-speed Multiprotocol Label Switching (MPLS) networks, specifying the basic principles of label switching, alternative routing optimization mechanisms, error recovery problems and virtual private network implementation solutions. The main goal of MPLS is to integrate IP traffic with high-speed optical networks, which are becoming increasingly accessible. On the other hand, traffic speed is only one aspect of QoS; another key dimension is the ability to recover quickly from error. Therefore, the most important task of this paper is to optimize the use of network bandwidth without using too essential information.