Abstract: Systems and methods for computing paths through a network are provided. A method, according to one implementation, includes the step of receiving information regarding a path through a network from a source node via one or more intermediate nodes to a destination node, whereby the path is loosely defined by a user as a partially-completed route through the network using one or more network resources. The method also includes the step of utilizing the information regarding the path to automatically compute a completed home route from the source node to the destination node while attempting to retain as many of the one or more intermediate nodes of the path as possible.

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: Systems and methods for path computation of a service in a multi-layer network including a client layer and a server layer include determining correlations between the client layer and the server layer; assigning data to one of client layer links and server layer links based on diversity between one another responsive to the determined correlations; and determining a resiliency path for a service from a current path using the data to determine diversity between the resiliency path and the current path in the client layer and the server layer.

Abstract: A method for bandwidth management in an optical broadcast network includes signaling, for a new optical broadcast service, from an originating node to all nodes in the optical broadcast network, wherein the signaling identifies a wavelength or portion of spectrum associated with the new optical broadcast service; at each of the nodes, checking for contention by the new optical broadcast service; responsive to identifying contention at one of the nodes, signaling the identified contention back to the originating node; and responsive to no contention at any of the nodes, processing the signaling, storing an update of the new optical broadcast service, and either forwarding the signaling to peer nodes or terminating the signaling.

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 of statistical multiplexing with one of Layer 0 Flexible Grid optical spectrum and Layer 1 Time Division Multiplexed (TDM) bandwidth in a multi-layer network includes obtaining a sampling of bandwidth usage over time on ports and links in the multi-layer network for one of Layer 0 and Layer 1 traffic using a plurality of statistical parameters, wherein the plurality of statistical parameters are defined for the one of Layer 0 and Layer 1 traffic; monitoring the plurality of statistical parameters; and triggering based on the monitoring one of i) adjustments to the one of Layer 0 and Layer 1 traffic and ii) adjustments to routing parameters on the links for new traffic, wherein the triggering is one of through a control plane and a Software Defined Networking (SDN) controller.

Abstract: Systems and methods for horizontal synchronization are implemented by a first node with a second node adjacent to the first node in a network with a control plane. The horizontal synchronization manages and corrects for a state of a service which is resizable. The systems and methods include providing a first horizontal synchronization message to the second node with a first state comprising the state of the service at the node and a first size comprising a size of the service at the node; receiving a second horizontal synchronization message from the second node with a second state comprising the state of the service at the second node and a second size comprising a size of the service at the second node; detecting a mismatch of the service with the second node based on the second horizontal synchronization message; and performing a recovery action to correct the mismatch.

Abstract: Systems and methods for horizontal synchronization are implemented by a first node with a second node adjacent to the first node in a network with a control plane. The horizontal synchronization manages and corrects for a state of a service which is resizable. The systems and methods include providing a first horizontal synchronization message to the second node with a first state comprising the state of the service at the node and a first size comprising a size of the service at the node; receiving a second horizontal synchronization message from the second node with a second state comprising the state of the service at the second node and a second size comprising a size of the service at the second node; detecting a mismatch of the service with the second node based on the second horizontal synchronization message; and performing a recovery action to correct the mismatch.

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: Systems and methods for path computation of a service in a multi-layer network including a client layer and a server layer include determining correlations between the client layer and the server layer; assigning data to one of client layer links and server layer links based on diversity between one another responsive to the determined correlations; and determining a resiliency path for a service from a current path using the data to determine diversity between the resiliency path and the current path in the client layer and the server layer.

Abstract: A Make-Before-Break (MBB) method, in a node operating in a network with a control plane, decoupling the control plane from a data plane, includes, for a connection operating on a path in the network, determining a reserved connection on a new path, through the control plane, wherein the reserved connection has zero bandwidth; signaling the reserved connection on the new path; creating the reserved connection in the control plane while suspending implementation in the data plane due to the zero bandwidth; and releasing the connection on the path and modifying the reserved connection on the new path to establish the connection on the new path.

Abstract: Systems and methods providing resiliency between a server layer and a client layer include determining a minimal spanning tree in the client layer; determining a Steiner tree in the server layer based on vertices associated with the minimal spanning tree in the client layer; and determining one or more resiliency paths in the client layer based on the minimal spanning tree and the Steiner tree, wherein the one or more resiliency paths are added to the minimal spanning tree in the client layer based on potential failures in the Steiner tree. For example, the server layer is an optical layer and the client layer is a Time Division Multiplexing (TDM) layer.

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.