A communication method, comprising: • obtaining, by a database network element that includes a structured data storage function, SDSF, network element, training data, wherein the training data comprises service transmission data and network data (S 501, S 601, S 701), whereby the service transmission data includes at least one of: an IP 5-tuple; a size of a data packet; a time for the data packet; a service type; service experience; an extended field, and whereby the network data includes at least one of: an IP address of a terminal; a port number of the terminal; a terminal type; terminal location information; a time; a DNN; a network congestion condition; • sending, by the database network element, the training data to a data analytics network element that includes a network data analytics, NWDA, network element (S 504, S 604, S 704), whereby the data analytics network element generates first information based on the training data, based on both the service transmission data and the network data (S 505, S 605, S 705); • receiving, by the database network element, first information from the data analytics network element, wherein the first information comprises a first feature index list set, a service identifier corresponding to each feature index list in the first feature index list set, and a data network name, DNN, corresponding to the service identifier, wherein each feature index list corresponds to a service type indicated by the service identifier, and each feature index list contains for each feature among a plurality of features of the service type a different index among a plurality of indices (S 506, S 606, S 706); • receiving, by the database network element from a control plane network element that includes a control plane function, CPF, network element, which includes an access and mobility management function, AMF, network element; a session management function, SMF, network element; or a policy control function, PCF, network element, a DNN corresponding to a first session (S 508, S 608, S 708); • querying, by the database network element, the first information based on the DNN corresponding to the first session, to obtain second information, wherein the second information comprises a second feature index list set corresponding to the DNN corresponding to the first session and a service identifier corresponding to each feature index list in the second feature index list set (S 509, S 609, S 709); • sending, by the database network element, the second information to the control plane network element (S 510, S 610, S 710). • obtaining, by a database network element that includes a structured data storage function, SDSF, network element, training data, wherein the training data comprises service transmission data and network data (S 501, S 601, S 701), whereby the service transmission data includes at least one of: an IP 5-tuple; a size of a data packet; a time for the data packet; a service type; service experience; an extended field, and whereby the network data includes at least one of: an IP address of a terminal; a port number of the terminal; a terminal type; terminal location information; a time; a DNN; a network congestion condition; whereby the service transmission data includes at least one of: an IP 5-tuple; a size of a data packet; a time for the data packet; a service type; service experience; an extended field, and whereby the network data includes at least one of: an IP address of a terminal; a port number of the terminal; a terminal type; terminal location information; a time; a DNN; a network congestion condition; • sending, by the database network element, the training data to a data analytics network element that includes a network data analytics, NWDA, network element (S 504, S 604, S 704), whereby the data analytics network element generates first information based on the training data, based on both the service transmission data and the network data (S 505, S 605, S 705); • receiving, by the database network element, first information from the data analytics network element, wherein the first information comprises a first feature index list set, a service identifier corresponding to each feature index list in the first feature index list set, and a data network name, DNN, corresponding to the service identifier, wherein each feature index list corresponds to a service type indicated by the service identifier, and each feature index list contains for each feature among a plurality of features of the service type a different index among a plurality of indices (S 506, S 606, S 706); • receiving, by the database network element from a control plane network element that includes a control plane function, CPF, network element, which includes an access and mobility management function, AMF, network element; a session management function, SMF, network element; or a policy control function, PCF, network element, a DNN corresponding to a first session (S 508, S 608, S 708); • querying, by the database network element, the first information based on the DNN corresponding to the first session, to obtain second information, wherein the second information comprises a second feature index list set corresponding to the DNN corresponding to the first session and a service identifier corresponding to each feature index list in the second feature index list set (S 509, S 609, S 709); • sending, by the database network element, the second information to the control plane network element (S 510, S 610, S 710).