Patent ID: 7529183

Claim:
A method of setting up a backup path in a transport network, wherein the transport network comprises a number of physically interconnected network elements, the method comprising: assigning labels to paths in the transport network; providing pre-configured backup tables to at least some network elements in the network, the backup tables defining the assigned labels and a route through the network for the backup path; activating the backup path at a first network element by inserting into a restoration resource available at a physical link along the route of the backup path the label of the backup path as defined by the backup table locally stored in the first network element; and upon receipt of the backup path label at a second network element, determining an output port of the second network element for the backup path using the backup table locally stored in the second network element, wherein a plurality of restoration resources available for the backup path form a restoration group, the backup tables define restoration groups per path labels, and the first and second network elements select a particular restoration resource from the restoration groups for the backup path according to pre-determined rules, wherein a path in the transport network is represented by a sequence of multiplex units transmitted at a predetermined frame position within consecutive frames and wherein idle frame positions in said frames constitute said restoration resources.