A method of localizing a defect location and a method of identifying a cause of a defect in an optical transport network (OTN). The method of localizing a defect location in an OTN includes generating tandem connection monitoring (TCM) coordinates consisting of a TCM level and trail information of an optical data unit (ODU) based on a relationship between an OTN line card (LC) and the ODU in the OTN, localizing the defect location in the OTN by converting the TCM level to a segment on the TCM coordinates, and identifying a root cause using a defect identification algorithm that traces back the cause of the defect in an opposite direction to that in which the defect is propagated based on an OTN layer structure.

Systems and methods for providing a data service through a packet-optical switch in a network include, subsequent to defining a loop-free forwarding topology for the data service in the network, if the packet-optical switch is a degree 2 site for the data service, providing the data service through the packet-optical switch at a Layer 1 protocol bypassing a partitioned packet fabric of the packet-optical switch; and if the packet-optical switch is a degree 3 or more site for the data service with multi-point connectivity, providing the data service through the packet-optical switch at the Layer 1 protocol and at a packet level using the partitioned packet fabric to provide the data service between the multi-point connectivity and to associated OTN connections for each degree of the degree 3 or more site.

The present disclosure discloses a protection switching method and a node. The method can include: receiving, by an intermediate node, a first protection switching request message sent by an upstream neighboring node, where the first protection switching request message is used to request to activate a first protection path, and the intermediate node is a node on the first protection path; determining, by the intermediate node, that the first protection path needs to occupy N1 timeslots, and selecting N1 timeslots for the first protection path from N2 available timeslots in a preset order; and sending, by the intermediate node, a second protection switching request message to the downstream neighboring node, where the second protection switching request message is used to request the downstream neighboring node to complete a cross-connection, on the first protection path, between the downstream neighboring node and the intermediate node based on the first group of timeslots.

In the optical transport system a transport frame generator divides a transport frame accommodating plural client signals into plural transmission signals. Subcarrier transmission units convert the signals into optical signals using different optical carriers and transmit the converted optical signals. Subcarrier reception units receive the transmitted optical signals and convert the optical signals into reception signals. A transport frame termination unit combines the reception signals to restore the transport frame. A time-demultiplexing processor time-demultiplexes the restored transport frame to be separated into the client signals. A time slot control unit determines a new time slot allocation when time-multiplexing the client signals in the transport frame and stops supply of electric power to a subcarrier transmission unit and a subcarrier reception unit that transmit and receive an optical signal to which the client signals are not allocated.

A system and method is disclosed in which circuitry of a first controller of a first node on a first path within a transport network receives a first signal indicating a failure within the first path from a second controller. The first node is an end node of the first path. A first client signal failure clear signal is received from a second node upstream of the first node on the first path. The first client signal failure clear signal indicates that a non-restorable fault has been resolved such that the first path can be considered for carrying data traffic. The non-restorable fault is a failure at the source. Subsequent to receiving the first signal indicating the failure within the first path, a backward defect indication clear signal is transmitted to the second node, the backward defect indication clear signal indicating an absence of a failure in the first path.

In an embodiment, the application provides a flexible Ethernet (FlexE) communication method, which includes: receiving, by a first network device by using a FlexE group, n first overhead blocks sent by a second network device, the FlexE group comprising n physical layer apparatuses (PHYs); and storing, by the first network device, the n first overhead blocks in n memories in the first time period. The method further includes simultaneously reading, by the first network device, the n first overhead blocks from the n memories, after a preset duration T starting from a moment at which a first overhead block is stored in a corresponding memory. The first overhead block is a last stored first overhead block in the n first overhead blocks, the duration T is greater than or equal to one clock cycle.

This application provides an isolation and recovery method and related network device for a case when one or more physical layer apparatuses (PHYs) in a flexible Ethernet group (FlexE group) are faulty. In the method, if a network device determines that a first overhead block corresponding to each current available PHY is stored in a corresponding memory, the network device determines that a FlexE group meets a PHY alignment condition, and starts to simultaneously read cached data from all memories. Therefore, there is no need to insert local fault LF code blocks to all clients, and there is no need to recreate a group. This effectively reduces the impact of a faulty PHY on client services carried by a normal PHY.

This application relates to a slot negotiation method and a device. The method includes: A transmitter sends a first FlexE overhead frame to a receiver, to request active/standby calendar switching. When the receiver is in a restart state, the receiver does not respond to the received first FlexE overhead frame. In addition, the RX sends a routine update second FlexE overhead frame to the transmitter. Determining that the second FlexE overhead frame is not a response to the first FlexE overhead frame, the transmitter sends a third FlexE overhead frame to request active/standby calendar switching again. According to the method in this application, incorrect calendar switching on the transmitter side caused by a mistaken response of the receiver can be avoided. This reduces the likelihood of a service interruption caused by the existing slot negotiation mechanism.

A method for assigning a severity to failure indications of network resources in a multilayered communication network includes in a processor, receiving one or a plurality of failure indications related to a failure of one or more network resources from a plurality of network resources in a communication network. A severity may be assigned to the one or said plurality of failure indications based on an impact on data, wherein assigning the severity includes at least one of: assigning a static severity based on a single traffic impact assessment in the communication network due to the one or more failed network resources, and assigning a dynamic severity based on continuous or periodic traffic impact assessments in the communication network due to the one or more failed network resources. The severity of the one or said plurality of failure indications may be outputted on an output device.

This application provides an isolation and recovery method and related network device for a case when one or more physical layer apparatuses (PHYs) in a flexible Ethernet group (FlexE group) are faulty. In the method, if a network device determines that a first overhead block corresponding to each current available PHY is stored in a corresponding memory, the network device determines that a FlexE group meets a PHY alignment condition, and starts to simultaneously read cached data from all memories. Therefore, there is no need to insert local fault LF code blocks to all clients, and there is no need to recreate a group. This effectively reduces the impact of a faulty PHY on client services carried by a normal PHY.