Patent ID: 7184663

Claim:
A method of protection switching traffic carried on an optical ring network, the ring network comprising a first optical ring, a second optical ring, a plurality of add/drop nodes and a hub node, the method comprising: detecting an interruption in a working path of traffic carried on the optical ring network, the working path extending between an origination node and a destination node, the interruption preventing the traffic from reaching the destination node from the origination node via the working path; isolating the interruption by opening the first optical ring at a first node adjacent in a first direction to the interruption and opening the second optical ring at a second node adjacent in a second direction to the interruption; terminating along a protection path terminable signals of the wavelength of the traffic in response to detecting the interruption, the protection path comprising the hub node and extending between the origination node and the destination node; reconfiguring the hub node so as to pass through the traffic in response to detecting the interruption; and without changing the wavelength of the traffic, forwarding the traffic along the protection path and through the hub node to the destination node.