Abstract: A node for a telecommunications network has a switch and a controller, for setting up a circuit along a main path through the network. The circuit associated with one or more precalculated alternate paths, for use in the event of failure of the main path. A check is made of whether one or more of the precalculated alternate paths is currently valid, based on whether the network resources needed by the alternate paths are currently available, according to a local dynamically updated routing database. If valid, then the controller sets up the switch and communicates with other nodes to set up one of the alternate paths for that circuit. This can reduce the chance of rerouting delay caused by the setting up of the alternate path failing owing to its resources no longer being available. Checking the precalculated path is still quicker than calculating an alternate path dynamically when needed.