A fixed network packet sending method, comprising: receiving (503, 602), by an access gateway device, a fixed network packet carried in a first fixed network session, wherein the fixed network packet comprises fixed network session characteristic information, and the fixed network session characteristic information is used to identify the fixed network packet, and wherein the fixed network packet is a data packet of a user in a fixed network; and sending (504, 603), by the access gateway device, the fixed network packet to a user plane function network element based on information about a first interface corresponding to the fixed network session characteristic information, wherein the first interface is an interface between the access gateway device and the user plane function network element; wherein the method further comprises: determining, by the access gateway device, the fixed network session characteristic information; and establishing, by the access gateway device, an association relationship between the fixed network session characteristic information and the information about the first interface, characterized in that there is a plurality of logical channels for the first interface, wherein each logical channel of the plurality of logical channels is identified by using a piece of information about the first interface, the information about the first interface is used to determine which logical channel of the first interface is used to send the fixed network packet from the access gateway device to the user plane function network element, the association relationship is a correspondence between the fixed network session characteristic information and the information about the first interface in a form of a table, and determining, by the access gateway device, the information about the first interface based on the correspondence. receiving (503, 602), by an access gateway device, a fixed network packet carried in a first fixed network session, wherein the fixed network packet comprises fixed network session characteristic information, and the fixed network session characteristic information is used to identify the fixed network packet, and wherein the fixed network packet is a data packet of a user in a fixed network; and sending (504, 603), by the access gateway device, the fixed network packet to a user plane function network element based on information about a first interface corresponding to the fixed network session characteristic information, wherein the first interface is an interface between the access gateway device and the user plane function network element; wherein the method further comprises: determining, by the access gateway device, the fixed network session characteristic information; and establishing, by the access gateway device, an association relationship between the fixed network session characteristic information and the information about the first interface, determining, by the access gateway device, the fixed network session characteristic information; and establishing, by the access gateway device, an association relationship between the fixed network session characteristic information and the information about the first interface, characterized in that there is a plurality of logical channels for the first interface, wherein each logical channel of the plurality of logical channels is identified by using a piece of information about the first interface, the information about the first interface is used to determine which logical channel of the first interface is used to send the fixed network packet from the access gateway device to the user plane function network element, the association relationship is a correspondence between the fixed network session characteristic information and the information about the first interface in a form of a table, and