# US 12,003,419 B2 · Method and apparatus for assigning network address prefix > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,003,419 B2 - Document ID: US12003419B2 - Status: Granted - Kind: B2 - Application number: 18/034,796 - Filed: 2021-09-27 - Published: 2023-12-21 - Granted: 2024-06-04 - Earliest claimed: 2020-11-04 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Wen Zhang; Yong Yang; Yingjiao He - Web page: https://patentgrep.com/patent/US12003419B2 ## CPC - H04L 45/748: using longest matching prefix - H04L 45/42: Centralised routing - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Embodiments of the present disclosure provide methods and apparatuses for assigning network address prefix. A method performed by a control plane function may comprise: receiving, from a terminal device, a request for assigning a network address prefix; determining whether the network address prefix is assigned by the control plane function or a user plane function; transmitting, to the user plane function, a PFCP Session Modification Request for requesting the user plane function to assign the network address prefix, if it is determined that the network address prefix is assigned by the user plane function; receiving, from the user plane function, a PFCP Session Modification Response including an assigned network address prefix; and transmitting the assigned network address prefix to the terminal device. The specific procedure for the terminal device to obtain the network address prefix from a network entity not directly requested by the terminal device may be defined. ## Claims ### Claim 1 A method performed by a control plane function, comprising: receiving, from a terminal device, a request for assigning a network address prefix; determining whether the network address prefix is to be assigned by the control plane function or a user plane function; transmitting, to the user plane function, a Packet Forwarding Control Protocol, PFCP, Session Modification Request for requesting the user plane function to assign the network address prefix, if it is determined that the network address prefix is to be assigned by the user plane function; receiving, from the user plane function, a PFCP Session Modification Response including an assigned network address prefix; and transmitting the assigned network address prefix to the terminal device, wherein the PFCP Session Modification Request includes a first parameter indicating that the user plane function is delegated to assign the network address prefix, and wherein the PFCP Session Modification Response includes a second parameter indicating assigned network address prefix by the user plane function; wherein the PFCP Session Modification Request includes a field for IPv6 Prefix Delegation Bits and/or a field for IPv6 Prefix Length; wherein the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length indicates a length of the network address prefix, or the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length is set to zero to indicate that the user plane function determines the length of the network address prefix based on a local configuration. ### Claim 2 (depends on 1) The method according to claim 1, wherein the first parameter or the second parameter comprises a field for IPv6 Prefix Delegation Bits and/or a field for IPv6 Prefix Length. ### Claim 3 (depends on 2) The method according to claim 2, wherein the IPv6 Prefix Delegation bits and/or IPv6 Prefix Length is set to zero. ### Claim 4 (depends on 1) The method according to claim 1, wherein the assigned network address prefix is an internet protocol version 6, IPv6, prefix. ### Claim 5 (depends on 1) The method according to claim 1, wherein the PFCP Session Modification Response comprises an information element for IP address of the terminal device; and wherein the information element for IP address of the terminal device comprises the second parameter. ### Claim 6 (depends on 5) The method according to claim 5, wherein an information element of Updated Packet Detection Rule, PDR includes the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length. ### Claim 7 (depends on 1) The method according to claim 1, wherein the control plane function comprises a session management function, SMF, and/or a packet data network gateway-control plane, PGW-C. ### Claim 8 A method performed by a user plane function, comprising: receiving, from a control plane function, a Packet Forwarding Control Protocol, PFCP, Session Modification Request for requesting the user plane function to assign a network address prefix to a terminal device; transmitting, to the control plane function, a PFCP Session Modification Response including an assigned network address prefix, wherein the PFCP Session Modification Request includes a first parameter indicating that the user plane function is delegated to assign the network address prefix, and wherein the PFCP Session Modification Response includes a second parameter indicating assigned network address prefix by the user plane function; wherein the PFCP Session Modification Request includes a field for IPv6 Prefix Delegation Bits and/or a field for IPv6 Prefix Length; wherein the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length indicates a length of the network address prefix, or the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length is set to zero to indicate that the user plane function determines the length of the network address prefix based on a local configuration. ### Claim 9 (depends on 8) The method according to claim 8, wherein the user plane function determines the length of the network address prefix based on a local configuration, or based on the PFCP Session Modification Request from the control plane function. ### Claim 10 (depends on 8) The method according to claim 8, wherein the first parameter or the second parameter comprises a field for IPv6 Prefix Delegation Bits and/or a field for IPv6 Prefix Length. ### Claim 11 (depends on 10) The method according to claim 10, wherein the IPv6 Prefix Delegation bits and/or IPv6 Prefix Length is set to zero. ### Claim 12 (depends on 8) The method according to claim 8, wherein the assigned network address prefix is an internet protocol version 6, IPv6, prefix. ### Claim 13 (depends on 8) The method according to claim 8, wherein the second message comprises an information element for IP address of the terminal device; and wherein the information element for IP address of the terminal device comprises the second parameter. ### Claim 14 (depends on 13) The method according to claim 13, wherein an information element of Updated Packet Detection Rule, PDR includes the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length. ### Claim 15 (depends on 14) The method according to claim 14, wherein the control plane function comprises a session management function, SMF, and/or packet data network gateway-control plane, PGW-C. ### Claim 16 A control plane function, comprising: one or more processors; and one or more memories comprising computer program codes, the one or more memories and the computer program codes configured to, with the one or more processors, cause the terminal device at least to: receive, from a terminal device, a request for assigning a network address prefix; determine whether the network address prefix is to be assigned by the control plane function or a user plane function; transmit, to the user plane function, a Packet Forwarding Control Protocol, PFCP, Session Modification Request for requesting the user plane function to assign the network address prefix, if it is determined that the network address prefix is to be assigned by the user plane function; receive, from the user plane function, a PFCP Session Modification Response including an assigned network address prefix; and transmit the assigned network address prefix to the terminal device, wherein the PFCP Session Modification Request includes a first parameter indicating that the user plane function is delegated to assign the network address prefix, and wherein the PFCP Session Modification Response includes a second parameter indicating assigned network address prefix by the user plane function; wherein the PFCP Session Modification Request includes a field for IPv6 Prefix Delegation Bits and/or a field for IPv6 Prefix Length; wherein the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length indicates a length of the network address prefix, or the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length is set to zero to indicate that the user plane function determines the length of the network address prefix based on a local configuration. ### Claim 17 (depends on 16) The control plane function according to claim 16, wherein the first parameter or the second parameter comprises a field for IPv6 Prefix Delegation Bits and/or a field for IPv6 Prefix Length. ### Claim 18 A user plane function, comprising: one or more processors; and one or more memories comprising computer program codes, the one or more memories and the computer program codes configured to, with the one or more processors, cause the terminal device at least to: receive, from a control plane function, a Packet Forwarding Control Protocol, PFCP, Session Modification Request for requesting the user plane function to assign a network address prefix to a terminal device; transmit, to the control plane function, a PFCP Session Modification Response including an assigned network address prefix, wherein the PFCP Session Modification Request includes a first parameter indicating that the user plane function is delegated to assign the network address prefix, and wherein the PFCP Session Modification Response includes a second parameter indicating assigned network address prefix by the user plane function; wherein the PFCP Session Modification Request includes a field for IPv6 Prefix Delegation Bits and/or a field for IPv6 Prefix Length; wherein the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length indicates a length of the network address prefix, or the field for IPv6 Prefix Delegation Bits and/or the field for IPv6 Prefix Length is set to zero to indicate that the user plane function determines the length of the network address prefix based on a local configuration. ### Claim 19 (depends on 18) The user plane function according to claim 18, wherein the user plane function determines the length of the network address prefix based on a local configuration, or based on the PFCP Session Modification Request from the control plane function. ### Claim 20 (depends on 18) The user plane function according to claim 18, wherein the first parameter or the second parameter comprises a field for IPv6 Prefix Delegation Bits and/or a field for IPv6 Prefix Length.