A first base station, wherein the first base station is a base station using a 5th generation new access technology, 5G access technology, comprising: a first receiving module, configured to receive a first bearer setup request message initiated by user equipment, UE, wherein the first bearer setup request message is used to indicate that the first base station needs to set up a tunnel and set up a first bearer with a long term evolution, LTE, core network; a first sending module, configured to send a first tunnel endpoint to a core network device based on the first bearer setup request message, wherein the core network device is in the LTE core network, the first tunnel endpoint comprises a first tunnel endpoint identifier, TEID and a first transport layer address, the first tunnel endpoint is allocated by the first base station, and the first tunnel endpoint is used to indicate a destination of data transmitted in a downlink data transmission path of the first bearer; a second receiving module, configured to receive a second tunnel endpoint sent by the core network device, wherein the second tunnel endpoint comprises a second TEID and a second transport layer address, the second tunnel endpoint is allocated by the core network device, and the second tunnel endpoint is used to indicate a destination of data transmitted in an uplink data transmission path of the first bearer; and a first setup module, configured to complete setup of the first bearer with the core network device, for transmitting the uplink data and transmitting the downlink data; wherein completing the setup of the first bearer comprises: setting up a downlink bearer of the first bearer between the first base station and the core network device by using the first TEID and the first transport layer address; and setting up an uplink bearer of the first bearer between the first base station and the core network device by using the second TEID and the second transport layer address. a first receiving module, configured to receive a first bearer setup request message initiated by user equipment, UE, wherein the first bearer setup request message is used to indicate that the first base station needs to set up a tunnel and set up a first bearer with a long term evolution, LTE, core network; a first sending module, configured to send a first tunnel endpoint to a core network device based on the first bearer setup request message, wherein the core network device is in the LTE core network, the first tunnel endpoint comprises a first tunnel endpoint identifier, TEID and a first transport layer address, the first tunnel endpoint is allocated by the first base station, and the first tunnel endpoint is used to indicate a destination of data transmitted in a downlink data transmission path of the first bearer; a second receiving module, configured to receive a second tunnel endpoint sent by the core network device, wherein the second tunnel endpoint comprises a second TEID and a second transport layer address, the second tunnel endpoint is allocated by the core network device, and the second tunnel endpoint is used to indicate a destination of data transmitted in an uplink data transmission path of the first bearer; and a first setup module, configured to complete setup of the first bearer with the core network device, for transmitting the uplink data and transmitting the downlink data; wherein completing the setup of the first bearer comprises: setting up a downlink bearer of the first bearer between the first base station and the core network device by using the first TEID and the first transport layer address; and setting up an uplink bearer of the first bearer between the first base station and the core network device by using the second TEID and the second transport layer address. setting up a downlink bearer of the first bearer between the first base station and the core network device by using the first TEID and the first transport layer address; and setting up an uplink bearer of the first bearer between the first base station and the core network device by using the second TEID and the second transport layer address.