Patent ID: 8339939

Claim:
A method for re-routing traffic flow in a packet switched communications transport network having nodes interconnected to each other with links establishing Label Switched Paths (LSPs) across the network, in which detour LSPs are set for Fast Re-Route (FRR), comprising the steps of: receiving new, managed bandwidth information of links between nodes; checking free managed bandwidth on detour LSPs of links between nodes; recalculating FRR detour LSPs responsive to determining that the existing LSPs do not have enough managed bandwidth; optimizing all detour LSPs based on free capacity of the links between the nodes responsive to determining that no optimized LSP has been found based on free managed bandwidth, wherein the free managed bandwidth of a link is a link capacity minus a reserved bandwidth of the link; and re-establishing the detours on new computed LSPs without requiring reservation by sending a setup message for new detour LSPs responsive to determining that an optimized LSP has been found.