Based on WDM, optical transmission technologies have been increasingly developed to meet the explosive growth of Internet traffic and demand for large bandwidth. This work aims at enriching optical and all-optical communications by adding various techniques and concepts that useful for traffic engineering. The first field is about the design of a node architecture that is able to handle different traffic requirements and needs. Two switching and signaling techniques have been proposed to manage the service parameters related to the electronic and optical processing as well to setup the lightpaths. The second field is related to QoS provision in OLS networks. A prioritized QoS differentiation has been introduced for contention resolution to enable dynamic QoS provision for applications with various constraints based on wavelength conversion and optical buffering. The third field deals with OLS network planning and resources management. Dimensioning and optimization problem formulation at are addressed to help achieving an efficient network planning policy. Numerous protocols for resource management have been introduced to support admission control and provide congestion avoidance.