Patent ID: 7590131

Claim:
A method of establishing a path through a transport network, said network comprising a number of physically interconnected network elements (NEn−1, NEn, NEn−1); transmission signals being transported over physical connections between said network elements; each transmission signal being subdivided into frames of the same length, said frames being structured according to a multiplex hierarchy into multiplex units respectively representing paths through said network and repeating every frame thereby forming traffic streams multiplexed to form said transmission signals; said method comprising the steps of: assigning each traffic stream an identifier called hereinafter a path tag which is sent in said traffic stream on a regular basis; providing forwarding information (FT) in each network element along said path to be established; receiving (a 1 ) a new traffic stream at an input port (I 1 ) of a network element (NEn); checking (a 2 ) the path tag of the received traffic stream and determining (a 3 ) an appropriate output port (O 2 ) based on said path tag and the forwarding information (FT); and establishing (a 4 ) an internal cross-connection between said input port (I 1 ) and said previously determined output port (O 2 ), wherein the assigning each traffic stream the path tag includes assigning a multiplex unit in a corresponding traffic stream the path tag to be sent in the traffic stream with the multiplex unit, each multiplex unit represents the corresponding traffic stream such that a sequence of identical multiplex units transmitted along a same path form the corresponding traffic stream.