An address management method performed by a session management function, SMF, network element, the method comprising the steps of: a.) receiving (S 602), from a user plane function, UPF, network element serving a terminal or an operation administration and maintenance, OAM, network element, configuration information of the UPF network element, o wherein the configuration information of the UPF network element includes a correspondence, wherein in the correspondence an address pool identifier of an address pool managed by the UPF network element corresponds to an identifier of the UPF network element and session information, wherein the session information comprises either a data network name, DNN, or an IP address version; b.) determining (S 604) that an IP address needs to be assigned to a to-be established session of the terminal when the SMF network element receives a PDU session establishment request message from the terminal; c.) obtaining (S 605) session information of the to-be established session of the terminal from the PDU session establishment request message, wherein the session information of the to-be established session comprises either an IP address version of the to-be established session or a DNN of the to-be established session; d.) obtaining (S 606) an identifier of the UPF network element; e.) determining (S 607), based on the correspondence, based on the obtained identifier of the UPF network element and based on the obtained session information, the address pool identifiercontained the correspondence; f.) sending (S 608) a request message to a dynamic host configuration protocol, DHCP, server, wherein the request message carries the determined address pool identifier, the determined address pool identifier being used by the DHCP server to assign an unused IP address contained in an address pool corresponding to the determined address pool identifier to the to-be established session (S 608); and g.) receiving (S 610), from the DHCP server, a response message from the server, wherein the response message carries the unused IP address for the to-be session. a.) receiving (S 602), from a user plane function, UPF, network element serving a terminal or an operation administration and maintenance, OAM, network element, configuration information of the UPF network element, o wherein the configuration information of the UPF network element includes a correspondence, wherein in the correspondence an address pool identifier of an address pool managed by the UPF network element corresponds to an identifier of the UPF network element and session information, wherein the session information comprises either a data network name, DNN, or an IP address version; o wherein the configuration information of the UPF network element includes a correspondence, wherein in the correspondence an address pool identifier of an address pool managed by the UPF network element corresponds to an identifier of the UPF network element and session information, wherein the session information comprises either a data network name, DNN, or an IP address version; b.) determining (S 604) that an IP address needs to be assigned to a to-be established session of the terminal when the SMF network element receives a PDU session establishment request message from the terminal; c.) obtaining (S 605) session information of the to-be established session of the terminal from the PDU session establishment request message, wherein the session information of the to-be established session comprises either an IP address version of the to-be established session or a DNN of the to-be established session; d.) obtaining (S 606) an identifier of the UPF network element; e.) determining (S 607), based on the correspondence, based on the obtained identifier of the UPF network element and based on the obtained session information, the address pool identifiercontained the correspondence; f.) sending (S 608) a request message to a dynamic host configuration protocol, DHCP, server, wherein the request message carries the determined address pool identifier, the determined address pool identifier being used by the DHCP server to assign an unused IP address contained in an address pool corresponding to the determined address pool identifier to the to-be established session (S 608); and g.) receiving (S 610), from the DHCP server, a response message from the server, wherein the response message carries the unused IP address for the to-be session.