# US 2023/0058366 A1 · Managing Service Function Chains > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0058366 A1 - Document ID: US20230058366A1 - Status: Published application - Kind: A1 - Application number: 17/784,333 - Filed: 2020-03-03 - Published: 2023-02-23 - Earliest claimed: 2020-02-04 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Alfonso de Jesus Perez Martinez; Juan Jose Delgado Reimundez; Rodrigo Alvarez Dominguez - Web page: https://patentgrep.com/patent/US20230058366A1 ## CPC - H04L 41/5051: Service on demand, e.g. definition and deployment of services in real time - H04L 41/0894: Policy-based network configuration management - H04L 41/0895: Configuration of virtualised networks or elements, e.g. virtualised network function or OpenFlow elements - H04L 41/40: using virtualisation of network functions or resources, e.g. SDN or NFV entities - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 76/20: Manipulation of established connections - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A method (700) in a policy control function, PCF, of moving a session from a service function chain, SFC, to a new SFC, wherein the SFC comprises a first SF that modifies packets in the session. The method comprises determining (702) to update a second SF in the SFC for the session, determining (704) a new SFC for the session comprising new SFs, wherein the new SFs are selected based on the determined update to the second SF and information related to the packet modification performed by the first SF and (706) sending a first message to a session management function, SMF, comprising updated policy control rules for the session, wherein the updated policy control rules comprise an indication of the new SFC for the session. ## Claims ### Claim at position 1 1-29. (canceled) ### Claim 30 A method in a policy control function (PCF) of moving a session from a service function chain (SFC) to a new SFC, wherein the SFC comprises a first service function (SF) that modifies packets in the session, the method comprising: determining to update a second SF in the SFC for the session; determining a new SFC for the session comprising new SFs, wherein the new SFs are selected based on the determined update to the second SF and information related to the packet modification performed by the first SF; and sending a first message to a session management function, SMF, comprising updated policy control rules for the session, wherein the updated policy control rules comprise an indication of the new SFC for the session. ### Claim 31 (depends on 30) The method of claim 30 wherein the method is performed responsive to receiving a second message from the SMF comprising a request for updated policy control rules for the session, wherein the second message further comprises the information related to the packet modification performed by the first SF. ### Claim 32 (depends on 30) The method of claim 30 wherein the method is performed responsive to receiving a service continuity indicator for the session wherein the service continuity indicator indicates that the session should be maintained. ### Claim 33 (depends on 32) The method of claim 32 wherein the service continuity indicator is obtained by the PCF from a unified data repository (UDR) as part of a session establishment procedure for the session. ### Claim 34 (depends on 30) The method of claim 30 wherein determining a new SFC for the session comprising new SFs comprises: determining that the first SF will not be included in the new SFC; and selecting a compensatory SF as one of the new SFs, wherein the compensatory SF is configured to ensure TCP ACK number consistency between the SFC and the new SFC in view of the packet modification performed by the first SF in the SFC. ### Claim 35 A method in a session management function (SMF) of moving a session from a service function chain (SFC) to a new SFC, wherein the SFC comprises a first service function (SF) that modifies packets in the session, the method comprising: responsive to receiving a third message from a user plane function, UPF, associated with the session, the third message indicating that the first SF is modifying packets in the session, sending a second message to a policy control function (PCF) comprising a request for updated policy control rules for the session, wherein the second message comprises information related to the modification being performed by the first SF; receiving a first message from the PCF comprising the updated policy control rules for the session, wherein the updated policy control rules comprise an indication of a new SFC for the session, wherein the new SFC comprises new SFs selected by the PCF; and sending a fourth message to the UPF, the fourth message comprising the updated policy control rules for the session. ### Claim 36 (depends on 35) The method of claim 35 wherein the third message comprises one or more of: a 5 tuple for the session; a new 5 tuple for the session; a TCP ACK number for the session; and a TCP Sequence number for the session. ### Claim 37 (depends on 35) The method of claim 35 further comprising sending a fifth message to the UPF, the fifth message comprising an instruction to the UPF to commence SF Traffic behaviour reporting; and wherein the third message is received from the UPF in response to the fifth message. ### Claim 38 (depends on 35) The method of claim 35 wherein sending a fourth message to the UPF, the fourth message comprising the updated policy control rules for the session, further comprises: determining one or more detection rules and/or instruction rules based on the updated policy control rules for the session wherein at least one instruction rule comprises an indication of the new SFC; and sending the one or more detection rules and/or instruction rules to the UPF in the fourth message. ### Claim 39 (depends on 35) The method of claim 35 further comprising: receiving registration messages from a plurality of UPFs, each registration message comprising registration information to register one or more SFs associated with the UPF, the registration information comprising: for each SF in the one or more SFs, i) an identifier for the respective SF and ii) an indication of any packet modifications performed by the respective SF. ### Claim 40 (depends on 39) The method of claim 39 wherein each registration message comprises a PFCP Association Request. ### Claim 41 (depends on 39) The method of claim 39 further comprising: using the registration messages to select, from the plurality of UPFs, the UPF associated with the session. ### Claim 42 (depends on 39) The method of claim 39 further comprising receiving from the PCF, as part of a session establishment procedure for the session, an indication of a service continuity indicator for the session wherein the service continuity indicator indicates one of the following: that the session can be restarted; that the session can be broken and continued; or that the session should be continuous. ### Claim 43 (depends on 42) The method of claim 42 wherein if the service continuity indicator indicates that that the session should be continuous, the method further comprises: selecting, from the plurality of UPFs, a UPF with traffic modification capability as the UPF associated with the session. ### Claim 44 A method in a user plane function (UPF) of moving a session from a service function chain (SFC) to a new SFC, wherein the SFC comprises a first service function (SF) that modifies packets in the session, the method comprising: sending a third message to a session management function (SMF) the third message indicating that the first SF is modifying packets in the session; receiving from the SMF a fourth message, the fourth message comprising updated policy control rules for the session, wherein the updated policy control rules comprise an indication of a new SFC for the session; and moving the session from the SFC to the new SFC, based on the received updated policy control rules. ### Claim 45 (depends on 44) The method of claim 44 wherein the step of moving the session from the SFC to the new SFC further comprises: classifying packets comprised in the session using heuristic analysis; and determining from the updated policy control rules that the session should be moved to the new SFC based on the results of the step of classifying packets. ### Claim 46 (depends on 44) The method of claim 44 wherein the step of sending a third message to the SMF is performed responsive to receiving a fifth message from the SMF, the fifth message comprising an instruction to the UPF to commence SF Traffic behaviour reporting. ### Claim 47 (depends on 44) The method of claim 44 wherein the third message comprises one or more of: a 5 tuple for the session; a new 5 tuple for the session; a TCP ACK number for the session; and a TCP Sequence number for the session. ### Claim 48 (depends on 44) The method of claim 44 further comprising: sending a registration message to the SMF, the registration message comprising information to register one or more SFs associated with the UPF, comprising: for each SF in the one or more SFs, i) an identifier for the respective SF and ii) an indication of any packet modifications performed by the respective SF. ### Claim 49 (depends on 48) The method of claim 48 wherein the registration message comprises a PFCP Association Request.