A service transmission method, wherein the method comprises: obtaining, by a resource management node, an IP address pool; dividing, by the resource management node, the IP address pool into at least one IP address segment, and determining at least one tunnel endpoint identifier index based on the at least one IP address segment, wherein each IP address segment is allocated one tunnel endpoint identifier index used to identify the respective IP address segment; allocating, by the resource management node, the at least one IP address segment and the at least one tunnel endpoint identifier index to at least one user plane network element wherein the method further comprises: (i) notifying, by the resource management node, a first forwarding node of a correspondence between the at least one IP address segment and the at least one user plane network element; and notifying, by the resource management node, a second forwarding node of a correspondence between the at least one tunnel endpoint identifier index and the at least one user plane network element; or (ii) notifying, by the resource management node, a transmission control node of a correspondence among the at least one IP address segment, the at least one tunnel endpoint identifier index, and the at least one user plane network element, wherein the correspondence is used to instruct the transmission control node to: notify the first forwarding node of a correspondence between the at least one IP address segment and the at least one user plane network element, and notify the second forwarding node of a correspondence between the at least one tunnel endpoint identifier index and the at least one user plane network element; wherein the first forwarding node is located between the at least one user plane network element and a packet data network and in a network in which the resource management node is located; and wherein the second forwarding node is located between an access network and the at least one user plane network element and in the network in which the resource management node is located. obtaining, by a resource management node, an IP address pool; dividing, by the resource management node, the IP address pool into at least one IP address segment, and determining at least one tunnel endpoint identifier index based on the at least one IP address segment, wherein each IP address segment is allocated one tunnel endpoint identifier index used to identify the respective IP address segment; allocating, by the resource management node, the at least one IP address segment and the at least one tunnel endpoint identifier index to at least one user plane network element wherein the method further comprises: (i) notifying, by the resource management node, a first forwarding node of a correspondence between the at least one IP address segment and the at least one user plane network element; and notifying, by the resource management node, a second forwarding node of a correspondence between the at least one tunnel endpoint identifier index and the at least one user plane network element; or (ii) notifying, by the resource management node, a transmission control node of a correspondence among the at least one IP address segment, the at least one tunnel endpoint identifier index, and the at least one user plane network element, wherein (i) notifying, by the resource management node, a first forwarding node of a correspondence between the at least one IP address segment and the at least one user plane network element; and notifying, by the resource management node, a second forwarding node of a correspondence between the at least one tunnel endpoint identifier index and the at least one user plane network element; or (ii) notifying, by the resource management node, a transmission control node of a correspondence among the at least one IP address segment, the at least one tunnel endpoint identifier index, and the at least one user plane network element, wherein the correspondence is used to instruct the transmission control node to: notify the first forwarding node of a correspondence between the at least one IP address segment and the at least one user plane network element, and notify the second forwarding node of a correspondence between the at least one tunnel endpoint identifier index and the at least one user plane network element; wherein the first forwarding node is located between the at least one user plane network element and a packet data network and in a network in which the resource management node is located; and wherein the second forwarding node is located between an access network and the at least one user plane network element and in the network in which the resource management node is located.