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.

A transmission network system, data switching and transmission method, apparatus and equipment are provided. The transmission network system includes: a flexible Ethernet group located at a physical layer; at least one flexible Ethernet client carried over the flexible Ethernet group; a flexible Ethernet time slot control module, configured to map, according to a block sequence, service data coming from an upper layer onto the flexible Ethernet group, and recover, from a block sequence received by the flexible Ethernet group, corresponding service data; a flexible Ethernet switching module, configured to perform switching in a physical layer and transmission of service data according to the block sequence.

Provided are a method for determining and sending a multiframe, and a communication device. The method includes: for physical layers of different interface bandwidth speeds, determining a multiframe number of the multiframe to be n-th power of 2, where n is a minimum positive integer that causes the multiframe number greater than or equal to a number of timeslots of a physical layer, identifier values of the multiframe identifier for identifying the multiframe number are sequentially carried in preset positions of overhead blocks of respective frames constituting the multiframe, and the number of the identifier values of the multiframe identifier is the same as the multiframe number. The identifier values of the multiframe identifier are a preset number of consecutive “0”s and the preset number of consecutive “1”s in sequence.

A method for low-rate signal transmission on Optical Transport Networks is provided. In the method, a signal is mapped to a low-rate OPU of a low-rate ODU, wherein the low-rate ODU comprises an ODU overhead section and the low-rate OPU, the low-rate OPU comprises an OPU overhead section and an OPU payload section, the low-rate ODU has a bit rate of 1, 244, 160 Kbps±20 ppm, and the OPU payload section has a bit rate of 1, 238, 954.31 Kbps±20 ppm; OPU overhead bytes and ODU overhead bytes are added to corresponding overhead section; then, the low-rate ODU is multiplexed to an Optical channel Data Unit-k (ODUk) that has a bit rate higher than the bit rate of the low-rate ODU; finally, the ODUk is transmitted via the OTN.

Example embodiments of this application provide a method and an apparatus for transmitting a service flow based on FlexE. The method includes: sending, by a first network device, a first FlexE overhead frame to a second network device, where the first network device and the second network device transmit a service flow using a first FlexE group, and the first FlexE overhead frame includes FlexE group adjustment identification information and PHY information of a physical layer (PHY) included in a second FlexE group; receiving, by the first network device, a second FlexE overhead frame sent by the second network device, where the second FlexE overhead frame includes FlexE group adjustment acknowledgment identification information; adjusting, by the first network device, the first FlexE group to the second FlexE group; and sending, by the first network device, the service flow to the second network device based on the second FlexE group, to dynamically adjust a FlexE group.

This application provides a data transmission method, a communications apparatus, a network device, a communications system, a storage medium, and a computer program product, to resolve a current problem that bandwidth waste is relatively severe when a service is carried based on a FlexE technology. In this application, a frame structure of a fine-granularity service frame is newly defined, so that service data can be transmitted in a time division multiplexing mode by using an Ethernet (ETH) interface.

A clock synchronization method includes receiving, by a receiving apparatus, a plurality of data blocks using a plurality of physical layer modules (PHYs), where the plurality of data blocks include a plurality of head data blocks, performing, by the receiving apparatus, timestamp sampling on the plurality of data blocks to generate a plurality of receipt timestamps, aligning, by the receiving apparatus, the plurality of receipt timestamps using a first receipt timestamp as a reference, generating, by the receiving apparatus, a clock synchronization packet based on the plurality of data blocks, and writing, by the receiving apparatus, a value of a second receipt timestamp into the clock synchronization packet, where the second receipt timestamp is a receipt timestamp that is of a second data block and that is determined based on the plurality of aligned receipt timestamps.

Provided are a method and device for mapping, multiplexing, demapping and demultiplexing data are provided. The method includes: mapping an Ethernet service data stream the rate of which is m*100 Gb/s sequentially into m Optical Payload Unit Sub-frames (OPUC) and multiplexing the m OPUC into an Optical Payload Unit Frame (OPUCm) the rate of which is m*100 Gb/s according to the way of byte interleave; and adding an Optical Channel Data Unit (ODU) overhead to the head of the OPUCm to obtain an Optical Channel Data Unit Frame (ODUCm) the rate of which is m*100 Gb/s, wherein the frame structure of the OPUC consists of 4 rows and 3810 columns; the frame structure of the OPUCm consists of 4 rows and 3810*m columns; and the frame structure of the ODUCm consists of 4 rows and 3824*m columns, wherein m is a positive integer. The present disclosure improves the spectrum efficiency of optical fibers and the systematic flexibility and the compatibility.

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.

Systems, apparatus, and methods for packetized clocks may include a packet interface to carry the rate of a client to a sigma-delta modulator that generates a clock at the required rate inside the chip itself there by removing the need for off-chip analog PLLs. The packetized clock may include a packet interface that receives a flow credit packet that includes a plurality of flow credit counts, one flow credit count for each data flow, and forwards a flow credit count for each data flow to one of a plurality of clock generators to generate a new clock signal for each data flow.