A method for wireless communication, comprising: receiving, by a terminal device, a first message transmitted by a network device (120, 130), the first message comprising a cause parameter, wherein the first message is a reply message rejecting a previous protocol data unit, PDU, session establishment or modification request message, wherein the PDU session establishment or modification request message comprises a value of a first parameter, wherein the value of the first parameter is a value of a parameter in a first RSD in a user equipment, UE, route selection policy, URSP, rule matching a first application data stream; and ignoring or skipping using, by the terminal device and according to the cause parameter, a second route selection descriptor, RSD, unsatisfying a cause-parameter condition, wherein the cause-parameter condition is at least one condition indicated by the cause parameter which must be satisfied by the RSD for PDU session establishment or modification, the cause-parameter condition comprising at least one of: whether a rejection cause in the cause parameter indicates that a service and session continuity, SSC, mode is supported by the network device (120, 130); whether there is an allowed SSC mode in the cause parameter; or whether a combination of a data network name, DNN, and single-network slice selection assistance information, S-NSSAI, in the second RSD currently being considered under the cause-parameter condition differs from a combination of a DNN and S-NSSAI used for initiation of the previous PDU session, determining, according to the cause parameter, a third RSD satisfying the cause-parameter condition, and transmitting, by the terminal device, a second message to the network device via a fourth parameter or a value combination of the fourth parameter in the third RSD satisfying the cause-parameter condition, wherein the second message is used for requesting PDU session establishment or modification. receiving, by a terminal device, a first message transmitted by a network device (120, 130), the first message comprising a cause parameter, wherein the first message is a reply message rejecting a previous protocol data unit, PDU, session establishment or modification request message, wherein the PDU session establishment or modification request message comprises a value of a first parameter, wherein the value of the first parameter is a value of a parameter in a first RSD in a user equipment, UE, route selection policy, URSP, rule matching a first application data stream; and ignoring or skipping using, by the terminal device and according to the cause parameter, a second route selection descriptor, RSD, unsatisfying a cause-parameter condition, wherein the cause-parameter condition is at least one condition indicated by the cause parameter which must be satisfied by the RSD for PDU session establishment or modification, the cause-parameter condition comprising at least one of: whether a rejection cause in the cause parameter indicates that a service and session continuity, SSC, mode is supported by the network device (120, 130); whether there is an allowed SSC mode in the cause parameter; or whether a combination of a data network name, DNN, and single-network slice selection assistance information, S-NSSAI, in the second RSD currently being considered under the cause-parameter condition differs from a combination of a DNN and S-NSSAI used for initiation of the previous PDU session, whether a rejection cause in the cause parameter indicates that a service and session continuity, SSC, mode is supported by the network device (120, 130); whether there is an allowed SSC mode in the cause parameter; or whether a combination of a data network name, DNN, and single-network slice selection assistance information, S-NSSAI, in the second RSD currently being considered under the cause-parameter condition differs from a combination of a DNN and S-NSSAI used for initiation of the previous PDU session, determining, according to the cause parameter, a third RSD satisfying the cause-parameter condition, and transmitting, by the terminal device, a second message to the network device via a fourth parameter or a value combination of the fourth parameter in the third RSD satisfying the cause-parameter condition, wherein the second message is used for requesting PDU session establishment or modification.