OPTICAL RESTORATION METHOD IN OPTICAL NETWORKS CONTROLLED BY A L0 SDN CONTROLLER
Methods, systems, and optical nodes are disclosed. The problems caused by the time-consuming process of serial activation of optical nodes in a restore path are addressed by utilizing a controller that controls all optical nodes in a restore path, in a parallel fashion, for faster restoration of the restore path.
1 . A method comprising the steps of:
receiving, by circuitry of a software defined network L0 network controller, first network performance information of a transport network having a first path through the transport network including a head end node, a tail end node and a first intermediate node, the transport network having a second path through the transport network including the head end node, the tail end node and a second intermediate node wherein the second intermediate node is exclusive from the first intermediate node;
determining a location of a fault within the first path;
calculating first power adjustment parameters and first estimated passband attenuation parameters for the head end node, the tail end node and the second intermediate node;
passing, by the software defined network L0 network controller, a message to the head end node to cause the head end node to reduce a source of transmitter launch optical power on the second path;
configuring, by the software defined network L0 network controller, the head end node, the tail end node and the second intermediate node with the first power adjustment parameters and the first estimated passband attenuation parameters in parallel; and
receiving, by the software defined network L0 network controller, second network performance information from the head end node, the tail end node and the second intermediate node indicative of the performance of the second path subsequent to the head end node, the tail end node and the second intermediate node being configured with the power adjustment parameters and the estimated passband attenuation parameters; and
configuring, in a serial manner, the head end node, the second intermediate node and the tail end node with second power adjustment parameters and second estimated passband attenuation parameters based upon the second network performance information.
2 . The method of claim 1 , wherein the first path is a primary path within the transport network.
3 . The method of claim 1 , wherein the second path is a restoration path within the transport network.
4 . The method of claim 1 , wherein the first estimated passband attenuation parameters are calculated with information indicative of a line spread at the tail end node, the line spread being indicative of optical signal loading and optical signal attenuation.
5 . The method of claim 1 , wherein the software defined network L0 network controller calculates the second path when the fault is detected and wherein data traffic is carried by the second path only after the fault within the first path is determined.
6 . A transport network comprising:
a head end node having a first processor and first optical ports;
a tail end node having a second processor and second optical ports;
a database storing network topology information and network performance information;
a software defined networking L0 network controller having a third processor and an output interface, the third processor accessing the database to obtain a path through the transport network from the head end node to the tail end node using the network topology information in the database, computing first power adjustment parameters and first estimated passband attenuation parameters for the head end node and the tail end node using the network performance information, and outputting the first power adjustment parameters and first estimated passband attenuation parameters to the head end node and the tail end node in a parallel fashion via the output interface.
7 . The transport network of claim 6 , wherein the path is a restoration path.
8 . The transport network of claim 7 , wherein the optical node calculates the restoration path when a failure is detected and wherein data traffic is carried by the restoration path only after the failure in the primary path.
9 . The transport network of claim 7 , wherein the third processor of the software defined networking L0 network controller accesses the database and obtains the path from a plurality of predetermined restoration paths.