Abstract: Path computation systems and methods are provided herein. According to one embodiment, a method includes obtaining topological information representing a topology of at least a portion of a network. The topological information includes one or more nodes and one or more links, each link configured to connect a node with a neighboring node. Each node includes a plurality of internal components and a plurality of connections configured to interconnect the internal components. The method further includes running path computation through the topological information to determine a plurality of paths from a first internal component to a second internal component. Also, the method includes applying elimination rules during the path computation to filter out one or more paths detected as being invalid. The elimination rules are based on one or more predetermined path sequences that include at least two hops involving an unviable sequence of specific types of internal components.

Abstract: Systems and methods include, responsive to a fault affecting an optical service on an active path in an optical network operating at a frequency ?1 via an optical transceiver and having optical line protection via an optical protection switch, switching to an inactive path that now becomes the active path and finding a new route in the optical network for the inactive path that has the fault; responsive to being unable to find a route at the frequency ?1, switching the inactive path to a new route at a different frequency ?2; and implementing spectrum coordination relative to the inactive path to either determine the frequency ?1 is available on the new route or to find another new route for the inactive path where the frequency ?1 is available.

Abstract: Path computation systems and methods are provided herein. According to one embodiment, a method includes obtaining topological information representing a topology of at least a portion of a network. The topological information includes one or more nodes and one or more links, each link configured to connect a node with a neighboring node. Each node includes a plurality of internal components and a plurality of connections configured to interconnect the internal components. The method further includes running path computation through the topological information to determine a plurality of paths from a first internal component to a second internal component. Also, the method includes applying elimination rules during the path computation to filter out one or more paths detected as being invalid. The elimination rules are based on one or more predetermined path sequences that include at least two hops involving an unviable sequence of specific types of internal components.

Abstract: Systems and methods include, responsive to a fault affecting an optical service on an active path in an optical network operating at a frequency ?1 via an optical transceiver and having optical line protection via an optical protection switch, switching to an inactive path that now becomes the active path and finding a new route in the optical network for the inactive path that has the fault; responsive to being unable to find a route at the frequency ?1, switching the inactive path to a new route at a different frequency ?2; and implementing spectrum coordination relative to the inactive path to either determine the frequency ?1 is available on the new route or to find another new route for the inactive path where the frequency ?1 is available.

Abstract: A service modification method includes, in a node which is part of a network controlled by a control plane, routing a connection off of its home path to a current path which is at least partially disjoint from the home path and creating a reservation for the connection on the home path such that the connection can revert thereto; signaling a modification of the connection while it is on the current path; and updating the reservation based on the modification including signaling the modification to all nodes on the home path. The service modification method can further include reverting the connection to the home path with the modification. The updating can fail due to an inability to support the modification on the home path, and the service modification method can further include periodically retrying the updating the reservation based on the modification.

Abstract: A service modification method includes, in a node which is part of a network controlled by a control plane, routing a connection off of its home path to a current path which is at least partially disjoint from the home path and creating a reservation for the connection on the home path such that the connection can revert thereto; signaling a modification of the connection while it is on the current path; and updating the reservation based on the modification including signaling the modification to all nodes on the home path. The service modification method can further include reverting the connection to the home path with the modification. The updating can fail due to an inability to support the modification on the home path, and the service modification method can further include periodically retrying the updating the reservation based on the modification.

Abstract: A method implemented by a processing device for gridless optical routing and spectrum assignment on links in an optical network includes, responsive to one or more new channel requests, performing a path computation utilizing frequency markers to determine feasibility of the one or more new channel requests, wherein the optical spectrum is represented as a real line with the frequency markers indicative of used optical spectrum; allocating the one or more new channel requests based on the path computation and allocation criteria; and responsive to allocating the one or more new channel requests, updating the associated frequency markers on the real line.

Abstract: A method for control plane discovery includes a plurality of network elements transmitting an outbound control plane communication to generate path information of a path through the network elements. The transmitting includes receiving, by an intermediate network element of the network elements, the outbound control plane communication on an optical layer ingress port, appending, by the intermediate network element, an intermediate network element identifier of the intermediate network element to the path information in the outbound control plane communication, and transmitting, by the intermediate network element, the outbound control plane communication via an electrical layer egress port based on the intermediate network element comprising a layer changing drop port.

Abstract: Systems and methods of path computation and setup via a control plane in a network with partial connectivity in a photonic layer include responsive to one or more nodes in the photonic layer having partial connectivity, receiving connectivity information of the one or more nodes in signaling messages at an originating node providing setup messages; storing the connectivity information of the one or more nodes and utilizing the connectivity information for path computation; after path setup of a service through the one or more nodes, periodically sending probe signaling messages over the service; and receiving probe response messages containing updated connectivity information of the one or more nodes and storing the updated connectivity information.

Abstract: A method implemented by a processing device for gridless optical routing and spectrum assignment on links in an optical network includes, responsive to one or more new channel requests, performing a path computation utilizing frequency markers to determine feasibility of the one or more new channel requests, wherein the optical spectrum is represented as a real line with the frequency markers indicative of used optical spectrum; allocating the one or more new channel requests based on the path computation and allocation criteria; and responsive to allocating the one or more new channel requests, updating the associated frequency markers on the real line.

Abstract: A method for control plane discovery includes a plurality of network elements transmitting an outbound control plane communication to generate path information of a path through the network elements. The transmitting includes receiving, by an intermediate network element of the network elements, the outbound control plane communication on an optical layer ingress port, appending, by the intermediate network element, an intermediate network element identifier of the intermediate network element to the path information in the outbound control plane communication, and transmitting, by the intermediate network element, the outbound control plane communication via an electrical layer egress port based on the intermediate network element comprising a layer changing drop port.

Abstract: A method, in an intermediate node in a control plane network, includes receiving a setup message from an originating node, wherein the setup message is sent towards a terminating node on a computed path in the control plane network, and the setup message indicates associated Layer 0 attributes; validating the associated attributes/constraints based on locally available resources; and performing one of: forwarding the setup message on the path towards the terminating node when validation is successful; forwarding the setup message on the path towards the terminating node with updated information indicating a rejection cause and additional information when the validation is unsuccessful, but a modification of the Layer 0 attributes/constraints is possible; and forwarding a release message on the path back to the originating node with updated information indicating a rejection cause and additional information when the validation is unsuccessful and no modifications of the Layer 0 attributes/constraints are possi

Abstract: A method, in an intermediate node in a control plane network, includes receiving a setup message from an originating node, wherein the setup message is sent towards a terminating node on a computed path in the control plane network, and the setup message indicates associated Layer 0 attributes; validating the associated attributes/constraints based on locally available resources; and performing one of: forwarding the setup message on the path towards the terminating node when validation is successful; forwarding the setup message on the path towards the terminating node with updated information indicating a rejection cause and additional information when the validation is unsuccessful, but a modification of the Layer 0 attributes/constraints is possible; and forwarding a release message on the path back to the originating node with updated information indicating a rejection cause and additional information when the validation is unsuccessful and no modifications of the Layer 0 attributes/constraints are possi