A communications network remote node having a downstream optical circuit configured to receive downstream, DS, optical signals from an active main node and from a standby main node, the downstream optical circuit switchable between a working mode and a protection mode. Optical receivers are configured to receive the demultiplexed downstream optical signals and output encapsulated downstream client signals. Optical transmitters are configured to receive encapsulated upstream client signals and to transmit upstream, US, optical signals at upstream wavelengths carrying the encapsulated upstream client signals. An upstream optical circuit is configured to multiplex the upstream optical signals carrying the encapsulated upstream client signals and to send the upstream optical signals to both main nodes. Processing circuitry is configured to extract downstream client signals and alignment data from encapsulated downstream client signals and form encapsulated upstream client signals by encapsulating upstream client signals and alignment data.

An alarm processing method and apparatus is disclosed. Specifically, a mechanism of configuring and detecting an LOF pre-alarm is provided. A detection condition of the LOF pre-alarm is that it is detected that a frame alignment failure lasts for first duration. A detection condition of the LOF alarm is that it is detected that a frame alignment failure lasts for second duration. The second duration is less than the first duration. When detecting the LOF pre-alarm, a network device inserts a first maintenance signal frame. The first maintenance signal frame supports frame alignment. In other words, a network device that receives the first maintenance signal frame may perform normal frame alignment, so that no alarm is reported, for example, the LOF alarm is not triggered.

Systems and methods include receiving a plurality of symbols that are part of a defined Digital Signal Processing (DSP) frame for coherent optical communication, wherein the DSP frame structure has a messaging channel incorporated therein that includes a subset of the plurality of symbols; capturing multiple samples of the messaging channel; and determining a message in the messaging channel based on analysis of the multiple samples. The method can further include transmitting, in the messaging channel, a reply to the message with the reply being repeated multiple times. The analysis is performed prior to Forward Error Correction (FEC) decoding on the data path.

This application discloses a service data processing method and device. A transmit-end device may generate an optical transport network (OTN) encapsulated signal carrying service data, and generate at least n FlexO (flexible optical transport network) frames based on the OTN encapsulated signal and send the at least n FlexO frames, where r FlexO frames in the at least n FlexO frames carry service check data, and the service check data may be used to restore the service data when bit error rates of k FlexO frames are greater than a reference bit error rate. In this way, if no more than r physical ports included in a FlexO group interface fail, or a bit error rate of no more than r FlexO frames is greater than the reference bit error rate due to another reason, a receive-end device may restore the service data through a received FlexO frame.

A first network element includes trail trace identifier information in an optical network frame. The first network element obtains data to transmit over an optical network link to a second network element. The first network element generates an optical network frame with alignment marker bytes, which are followed by padding bytes. The optical network frame also includes overhead bytes following the padding bytes. The overhead bytes include a Multi-Frame Alignment Signal (MFAS) byte, a link status byte, and reserved bytes. The optical network frame also includes a payload bytes following the overhead bytes. The payload bytes encode at least a portion of the data to transmit to the second network element. The first network element inserts trail trace identifier information into the reserved bytes in the overhead bytes. The trail trace identifier information identifies the first network element as a source of the optical network frame.

Embodiments of this application disclose a service resource preconfiguration method and device, and a system. The method includes establishing a first working path, sending a first path message from a first node to a second node, the first path message including an instruction to the second node to preconfigure a second channel resource; and preconfiguring the second channel resource based on the first path message. Fast automatic service recovery can be implemented, and fault recovery performance can be improved.

A method to avoid sympathetic switches in path switching protection due to client protection switching includes monitoring a drop side Tandem Connection Monitoring (TCM) entity and a line side TCM entity for a connection, wherein the drop side TCM is provisioned between a drop port of the node and a second drop port of a corresponding node, and wherein the line side TCM entity is provisioned between a plurality of line ports of the node and a second plurality of line ports of the corresponding node; responsive to detecting defects in both the drop side TCM entity and the line side TCM entity on a working line, implementing path protection switching of the working line; and, responsive to detecting defects only in the drop side TCM entity, implementing path protection switching of the working line responsive to persistence of the defects.

A method and a device for realizing an optical channel data unit (ODU) shared protection ring (SPRing) are disclosed. The method includes: first, receive an ODUj, wherein the ODUj carries an ODUi; then, perform de-multiplexing processing to obtain the ODUi from the ODUj; next, multiplex the ODUi to an optical channel data unit k (ODUk); meanwhile, keep monitoring the ODUk; and when the monitoring result that is obtained through monitoring the ODUk indicates that a failure has occurred, perform a switching on the ODUi; wherein i, j, k are integers equal to or larger than 0, k is larger than j, j is larger than i, and i, j, k are used to indicate different rates of respective optical channel data unit (ODU) signals.

A method, implemented in a network with a control plane, is described for creating a compound Service Level Agreement (SLA) call for a Time Division Multiplexing (TDM) service in the network. The method includes creating the call with a non-preemptible component and a preemptible component, the compound SLA comprising the non-preemptible component and the preemptible component; implementing endpoints for the call at a source node and a destination node; and responsive to a preemption event in the network, removing the preemptible component at the endpoints. A node and network are also described.

Providing protection to network traffic includes sending a Pseudowire protection configuration parameter for configuring a standby Pseudowire between a source node and a destination node, receiving a Pseudowire configuration acknowledgement indicating whether the Pseudowire protection configuration parameter has been accepted by the destination node, and in the event that the Pseudowire protection configuration parameter has been accepted by the destination node, using the standby Pseudowire, wherein the standby Pseudowire's configured based at least in part on the Pseudowire protection configuration parameter.