Abstract: A data transmission method and apparatus are provided. One example method involves establishing two tunnels between an access network device and a user plane function network element, where the two tunnels may be tunnels used for downlink data transmission or tunnels used for uplink data transmission. When communicating with the user plane function network element, the access network device may transmit two data packets. In this way, when one data packet is lost, the receive end may further receive the other data packet.

Abstract: Example communication methods and apparatus are described. One example method includes sending a first request message by a terminal device to a first device, where the first request message includes a second identifier identifying that access of the terminal device to a target server is continuous access. The first device sends the first request message to a second device based on the second identifier and a third mapping relationship indicating a correspondence between the second identifier and the second device. The second device sends the first request message to the target server based on the second identifier and a second mapping relationship indicating a correspondence between the second identifier and the target server.

Abstract: A communication method includes a first device that receives a first message for requesting a time synchronization service for a terminal device. The first device determines first information based on subscription information of the terminal device, and determines a third device configured to provide the time synchronization service, and sends the first information to the third device. The subscription information includes at least one of indication information, one or more types of time source, or one or more clock accuracies, the first information includes a first type and/or a first clock accuracy, the one or more types include the first type, and the one or more clock accuracies include the first clock accuracy.

Abstract: A method includes: a communication device determines a time offset value based on scheduling and orchestration information and time of arrival, and sends the time offset value to an application network element. The scheduling and orchestration information indicates a scheduling moment, the time of arrival indicates a moment at which a first data packet in a service flow arrives at the communication device, and the time offset value is a difference between the moment at which the first data packet arrives at the communication device and the scheduling moment.

Abstract: A communication method includes receiving, by a terminal device, first clock source information. The first clock source information corresponds to clock source information of a wireless communication system. The first clock source information indicates that a fifth generation (5G) system clock is useable as a clock source. The method further includes sending, by the terminal device, the first clock source information to an adjacent device.

Abstract: Embodiments of this application provide a communication method and apparatus. The method includes: A session management function network element determines a first user plane function network element based on first information of a service, association information between the first user plane function network element and a second user plane function network element supporting the service, and information of services provided by the second user plane function network element, and sends second information of the service and a first identifier to the first user plane function network element to indicate to send a packet of the service through a first flow that meeting a requirement of the service. This ensures that a packet forwarding path meets a requirement of a service of a terminal device, improves packet forwarding flexibility and efficiency, and implements dynamic scheduling based on a service capability of a network element and a network status.

Abstract: Embodiments of this application provide a method for determining an application server and an apparatus. The method includes: A first network element obtains a characteristic parameter of a candidate application server. The first network element obtains a network status of a serving link, where the serving link is a link from a terminal to a DN in which the candidate application server is located. The first network element determines a target application server from the candidate application server based on the characteristic parameter of the candidate application server and the network status of the serving link. Therefore, compared with an existing method, in the method in this application, resources in a network can be better used, and the selected target application server can better execute a service of the terminal device, to improve user experience.

Abstract: A quality of service monitoring method, system, and a device, where the quality of service monitoring method includes: obtaining, by a first device, information about a first transmission delay for packet transmission between the first device and a second device for a terminal; sending, by the first device, the information about the first transmission delay to a third device; and sending, by the first device at a first moment, information related to the first moment to the third device, where the information about the first transmission delay and the information related to the first moment are used to determine information about a second transmission delay for packet transmission between the second device and the third device for the terminal.

Abstract: In a method for network communications, a session management network element receives an identifier of a session of a terminal device, an identifier of a port corresponding to the session, and a processing policy of a data flow for the port. The session management network element determines, according to the identifier of the port, a type of a first device corresponding to the port. The session management network element then sends, according to the determined type of the first device, processing policy information to the first device. The processing policy information comprises the identifier of the port and the processing policy of the data flow.

Abstract: In an embodiment, a session management function (SMF) network element obtains first information identifying a data stream, where the first information is used to instruct a transmit end to send a user stream using the data stream and to instruct a receive end to receive the user stream using the data stream; and the receive end is an access network element, and the transmit end is a user plane function network element, or vice versa; the SMF network element sends the first information to the user plane function network element and/or the access network element; the SMF network element obtains second information, where the second information is used to indicate a forwarding rule of transmitting the user stream by the user plane function network element on a data network side; and the SMF network element sends the second information to the user plane function network element.

Abstract: This application provides a route configuration method and an apparatus, and relates to the field of communication technologies. The route configuration method includes: A session management network element obtains VLAN information of a first port, where the first port is a port, which corresponds to an established PDU session of a first terminal, on a first user plane network element, and the first user plane network element is a user plane network element that serves the first terminal. The session management network element generates first routing information and second routing information based on the VLAN information of the first port, and sends the first routing information and the second routing information to the first user plane network element.

Abstract: This application describes examples of a wireless communication method, a communication apparatus, and a communication system. In one example, the method includes obtaining, by a radio access network device, a first time point at which a downlink data flow of a first application arrives at the radio access network device and a second time point at which a downlink data flow of a second application arrives at the radio access network device. When the first time point and the second time point meet a first condition, the radio access network device determines, based on a load capability of the radio access network device, a third time point at which the downlink data flow of the first application arrives at the radio access network device. The third time point is an adjusted time point at which the downlink data flow of the first application arrives at the radio access network device.

Abstract: A session management method and an apparatus, where the method includes: obtaining, by a session management function (SMF), a point-to-point protocol over Ethernet (PPPoE) message from a user equipment; assigning a PPPoE session identifier and/or an Internet Protocol (IP) address to the user equipment; and sending, by the SMF, the assigned PPPoE session identifier and/or IP address to the user equipment, to establish a PPPoE connection between the user equipment and a network side device. The method is performed after a packet data unit (PDU) session is successfully established. The SMF sends the PPPoE session identifier and/or the IP address to the user equipment. In this case, the user equipment can store a correspondence between the established PDU session and a PPPoE session, such that the user equipment accesses a 5G core network (CN) through a fixed network.

Abstract: Example communication methods and apparatus are described. One example method includes determining a first encapsulation identifier corresponding to an Ethernet session by a control plane network element and sending the first encapsulation identifier corresponding to the Ethernet session to a user plane network element, where the first encapsulation identifier is used to instruct the user plane network element to process a data packet corresponding to the Ethernet session based on the first encapsulation identifier. The terminal device determines the first encapsulation identifier corresponding to the Ethernet session and encapsulates an uplink data packet based on the first encapsulation identifier, where the uplink data packet is a data packet triggered by an application program bound to the Ethernet session. The encapsulated data packet is mapped to the Ethernet session corresponding to the first encapsulation identifier for transmission based on the first encapsulation identifier.

Abstract: A communication method includes: determining, based on first indication information and second indication information, a transmit end and a receive end that communicate with each other by using a data flow, to indicate that a first device is the transmit end and the second indication information is used to indicate that a second device is the receive end, or to indicate that the first device is the receive end and the second indication information is used to indicate that the second device is the transmit end; obtaining, bandwidth information of the data flow; and sending, data flow information and the bandwidth information to indicate at least one of a port identifier of the transmit end and a port identifier of the receive end, and the port identifier of the transmit end, the port identifier of the receive end, and the bandwidth information are used to create the data flow.

Abstract: A session management network element determines whether a first communication apparatus and a second communication apparatus have a redundancy functionality, receives a session establishment request message from a first terminal device, to request to establish a first session between the first terminal device and a data network. When both the first communication apparatus and the second communication apparatus have the redundancy functionality, and the first session is a redundant session, selects a first user plane function network element to establish the first session, where the second user plane function network element is configured to establish a second session, the first session is a redundant session of the second session, and the first session and the second session are for communication between the first communication apparatus and the second communication apparatus.

Abstract: A time-sensitive networking communication method and an apparatus, where the method may include: receiving, by a policy control network element, forwarding policy information of time sensitive networking (TSN) traffic; triggering the policy control network element to manage a quality of service (QoS) flow corresponding to the TSN traffic; determining a user terminal corresponding to the TSN traffic; determining, in a QoS flow corresponding to the user terminal, the QoS flow corresponding to the TSN traffic; creating or updating, according to the forwarding policy information, a QoS policy of the QoS flow corresponding to the TSN traffic; and sending the QoS policy to a session management network element, where the forwarding policy information includes traffic information of the TSN traffic and an identifier of a port that transmits the TSN traffic.

Abstract: In an embodiment, a session management function (SMF) network element obtains first information identifying a data stream, where the first information is used to instruct a transmit end to send a user stream using the data stream and to instruct a receive end to receive the user stream using the data stream; and the receive end is an access network element, and the transmit end is a user plane function network element, or vice versa; the SMF network element sends the first information to the user plane function network element and/or the access network element; the SMF network element obtains second information, where the second information is used to indicate a forwarding rule of transmitting the user stream by the user plane function network element on a data network side; and the SMF network element sends the second information to the user plane function network element.

Abstract: Embodiments of the present disclosure disclose a session management method and an apparatus. The technology is specifically related to sending, by user equipment, a NAS message to an AGF, where the NAS message includes a PDU session establishment request message used to request to establish a PDU session, receiving, by the user equipment, a PDU session establishment accept message returned by a network side device, and establishing, by the user equipment, an access session with the AGF, where the access session is an access session related to the PDU session. The user equipment sends the NAS message to establish the PDU session, and establishes the access session with the AGF. Because the access session is related to the PDU session, the user equipment can map the PDU session to the access session, so that the user equipment accesses a 5G CN through a fixed network.

Abstract: This application discloses a data transmission method, a link quality detection method, a communication apparatus, and a storage medium, and relates to the communication field. The data transmission method includes: A first user plane function receives data from a first terminal, where the data is data sent to a second terminal; and the first user plane function sends the data to a second user plane function through a first QoS flow, where the second user plane function is a user plane function corresponding to the second terminal. In the data transmission method, data transmission is performed between the first user plane function and the second user plane function through the first QoS flow, and data transmission can also be performed between the first terminal and the first user plane function and between the second terminal and the second user plane function based on a QoS flow.