A method includes: generating indication information, where the indication information is used to indicate a resource allocation table corresponding to a first data unit in the plurality of data units; sending the indication information in a timeslot previous to a timeslot used to send the first data unit; and sending the plurality of data units, where a resource allocation table corresponding to each data unit is selected from a plurality of resource allocation tables in a cyclic manner, and a cyclically initial resource allocation table is the resource allocation table indicated by the indication information.

A data transmission method in an optical transport network includes: mapping first-type service data to a payload block at a specific location in a plurality of consecutive payload blocks, where the plurality of consecutive payload blocks occupy a payload area of an optical data unit (ODU) frame; mapping second-type service data to a payload block at any location in the plurality of consecutive payload blocks other than the at least one specific location; mapping the ODU frame to an optical transport unit (OTU) frame or a flexible OTN (FlexO) frame; and sending the OTU frame or the FlexO frame. In an applicable scenario, service data is transmitted in a hybrid manner.

At least a method and a device for transmitting data are disclosed. The method includes obtaining n FlexE signal streams, where a transmission rate of each FlexE signal stream is a first rate, distributing an i.sup.th FlexE signal stream into m signal sub-streams, where each of the m signal sub-streams carries a first identifier, which indicate that the signal sub-stream carrying the first identifier belongs to the i.sup.th FlexE signal stream, inserting a preset quantity of padding code blocks into each of the m signal sub-streams, to obtain m padded signal sub-streams, so that transmission rate of each of the m padded signal sub-streams is equal to that of a first optical module, where the rate of the first optical module is greater than the first rate/m, and less than the first rate, and sending the m padded signal sub-streams by using m first optical modules.

Provided is an OTN traffic management method of a traffic management apparatus included in an OTN line card that accepts OTN traffic and transmits the OTN traffic to a multilayer-integrated fabric switch; or accepts traffic, in units of cells, from the multilayer-integrated fabric switch and transmits, to a network, the OTN traffic that the OTN line card generates. The OTN traffic management method includes restoring a received Interlaken packet to an OTN frame; adding an ITMOH that contains information about an ODU payload size to the OTN frame; converting the OTN frame, to which the ITMOH has been added, into to fabric cell by further adding a fabric overhead; and transmitting the fabric cell to the multilayer-integrated fabric switch.

Method and apparatus for transporting client signals in an MN are illustrated. In one embodiment, the method includes: mapping a client signal into a first Optical Channel Data Tributary Unit (ODTU) frame including an ODTU payload area and an ODTU overhead area, such that a plurality of n-bit data units of the client signal are inserted into the ODTU payload area and number information is inserted into the ODTU overhead area; mapping the first ODTU frame into the OPUk frame, such that the plurality of n-bit data units are mapped into an OPUk payload part occupying at least one Tributary Slot (TS) of the OPUk payload area and the number information of the ODTU overhead area is mapped into a first OPUk overhead part of the OPUk frame; forming an Optical Channel Transport Unit-k (OTUk) frame including the OPUk frame for transmission.

A data transmission method, a transmitter, and a receiver, where the method includes obtaining constant bit rate (CBR) service data, performing physical coding sublayer (PCS) encoding on the CBR service data, inserting a rate adaptation code block in a PCS bitstream obtained by PCS encoding to perform rate adaptation on the PCS bitstream, mapping the adapted PCS bitstream to N timeslots of a flexible Ethernet (FlexE) frame, where N is a positive integer greater than or equal to one, and sending the FlexE frame, where FlexE overhead of the FlexE frame includes information indicating the N timeslots corresponding to the PCS bitstream. Hence, according to the data transmission method, the transmitter, and the receiver, the CBR service data may be mapped to a FlexE, and a carrying capability of the FlexE is improved.

An embodiment method includes: mapping a to-be-transmitted optical channel unit signal of n times a benchmark rate to X first optical channel physical link signals; adding a link sequence indicator overhead to each of the X first optical channel physical link signals, to generate X second optical channel physical link signals; and modulating and sending the X second optical channel physical link signals by using X preset optical modules in a one-to-one manner. A rate of the first optical channel physical link signal is m.sub.i times the benchmark rate, n≥2, X≥2, m.sub.i≥1, and $\underset{t-1}{\overset{X}{.Math.}}{m}_i=n.$

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.

Embodiments of this application provide a link group configuration method and an apparatus. The link group configuration method includes: obtaining, by a first network device, candidate groups to which M physical ports of the first network device belong respectively; obtaining, by the first network device from a second network device, candidate groups to which M physical ports of the second network device belong respectively; and selecting N physical links from M physical links, as a link group between the first network device and the second network device, based on the candidate groups to which the M physical ports of the first network device belong respectively and the candidate groups to which the M physical ports of the second network device belong respectively.

In various embodiments, a method is provided. In this method, a first signal is received from a master node, and is sampled to obtain a first sample. The first sample is then quantized to obtain a quantized form of the first sample. A first synchronization sequence is detected from the quantized form of the first sample at T2. First information is received from the master node and the first information is used to indicate a moment T1 at which the master node sends the first synchronization sequence. A second synchronization sequence is sent to the master node at T3. Second information received from the master node and the second information is used to indicate a moment T4 at which the master node detects a quantized form of the second synchronization sequence. Time synchronization is performed based on T1, T2, T3, and T4.