Systems and methods are described in which circuitry of a first controller of a first node receives a first signal indicating an optical loss of signal within the first path. Circuitry of a second controller of the first node on the first path within a transport network generates a second signal indicating a failure within the first path. The first controller accessing a network topology database determines that restoration of the first path would be ineffective due to there being no alternate path, and signals a second node downstream in the first path with the second signal indicating the failure within the first path, and a third signal indicating that restoration of the first path would be ineffective due to there being no alternate path.

The disclosure provides an interconnecting node for interconnecting first and second protected domains, the second protected domain comprising a working path and a protection path for linear protection in a network for traffic forwarding between two end-nodes. The interconnecting node comprises at least one interface for receiving first monitoring information from the first protected domain, a monitoring unit for detecting an isolation condition of the interconnecting node within the first protected domain based on the first monitoring information, and generating second monitoring information to be transmitted to the working path so that a failure in the working path is detectable based on the second monitoring information at a far-end node of the working path. If an isolation condition is detected, the monitoring unit starts transmitting alarm indication information to the working path for suppressing at the far-end node an alarm reporting regarding a failure in the working path.

Methods, nodes and control modules are disclosed. In the method, circuitry of a first node in a mesh network converts an optical layer in a working path between the first node and a second node, to a data stream in a digital layer. The working path carries data traffic from the first node to the second node in the optical layer of the mesh network when there is no failure in the working path. Circuitry of the first node in the mesh network detects a failure in the working path due to detection of an error in the data stream in the digital layer. The circuitry of the first node establishes, through transmission of at least one signal from the first node to the second node, a restoration path in the optical layer based on, at least in part, detection of the error in the data stream in the digital layer.

A method for path computation in a network includes determining dynamic link weights for links in the network, responsive to a request for a path, for a connection, between a source node and a destination node in the network with a requested bandwidth amount, wherein the dynamic link weights, for each link, are based on a current status of the link and a future status of the link; determining one or more paths for the request based on the dynamic link weights; and selecting a path of the one or more paths to minimize cost in the network. The method can be implemented through a Software Defined Networking (SDN) controller.

Embodiments of the invention disclose a communication method which includes: receiving, by the optical network unit (ONU) by using the first port or the second port, a wavelength switching request message delivered by the optical line terminal (OLT), where the wavelength switching request message carries second wavelength channel information and port information that is of the second port; switching, by the ONU, an operating wavelength channel of an optical module connected to the second port from a first wavelength channel to a second wavelength channel corresponding to the second wavelength channel information; and sending, by the ONU, a wavelength switching complete message to the OLT by using the first port. According to the communication method provided in embodiments of the present invention, quick wavelength switching is performed based on the second port, so that a service is not interrupted in a wavelength switching process, and user experience is better.

A network module for sending and/or receiving of data packages from a network arrangement located in a network with ring structure, wherein the data package includes at least one data package segment, a source address, a destination address and an identification number. The network module includes a first network interface and a second network interface, for receiving and/or sending of data packages via the ring structure, a processor configured to determine, based on the destination address, if data packages received are directed to the network module and to determine if the source address and/or the destination address are contained in a predefined list of the network participants, to determine, based on the source address and the identification number, if a copy of a data package directed to the network module is already created in a memory, to create a copy of the data package in the memory.

Systems and methods for path computation in an optical network include obtaining optical layer characteristics related to one or more optical paths in the optical network based in part on performance measurements in the optical network; responsive to service establishment or service restoration, determining a path from source to destination based on utilizing the optical layer characteristics to confirm physical validity of the path; and provisioning a service on the determined path from the source to the destination in the optical network.

An optical transceiver for use in network device in a packet network is provided. The network device may not be capable of providing a ring topology without use of the apparatus. The network device is configured to support at least two optical interfaces and an electrical interface, and coupled to an optical link. The optical transceiver includes a memory, a processor coupled to the memory, and a scheduler coupled to the processor. The scheduler of the optical transceiver is configured to perform as an information base for forwarding and transferring of packets and to use an optical link as a packet buffer.

The present disclosure provides dynamic performance monitoring systems and methods for optical networks to ascertain optical network health in a flexible and accurate manner. The present invention introduces accurate estimations for optical channel performance characteristics based either on existing channels or with a dynamic optical probe configured to measure characteristics on unequipped wavelengths. Advantageously, the dynamic performance monitoring systems and methods introduce the ability to determine physical layer viability in addition to logical layer viability.

A network component comprising a generalized multiprotocol label switching (GMPLS) control plane controller configured to implement a method comprising transmitting a message to at least one adjacent control plane controller, wherein the message comprises a Type-Length-Value (TLV) indicating Routing and Wavelength Assignment (RWA) information, wherein the TLV comprises a Node Attribute TLV, a Link Set TLV, or both, and wherein the TLV further comprises at least one sub-TLV indicating additional RWA information. A method comprising communicating an open shortest path first (OSPF) link state advertisement (LSA) message comprising a TLV with at least one sub-TLV to a GMPLS control plane controller, wherein the TLV comprises a Node Attribute TLV, a Link Set TLV, or both, and wherein the TLV further comprises at least one sub-TLV indicating RWA information.