Technique for internet protocol anchor relocation
A system and method for IP POP change for a user equipment are described. The approach is taken of assigning a new IP POP to the user equipment in an ongoing packet data unit session, while maintaining packet data transmission in that session. The new IP POP is brought into commission in stages within the session, with the uplink path being moved and then the downlink path.
1. A method for Internet Protocol (IP) Point of Presence (POP) change for a user equipment in a communication architecture, the communication architecture having a user plane for packet data communication of user data and a control plane for controlling the packet data communication, the method comprising:
managing a first communication path in the user plane between a user equipment and a first IP POP having a first IP address, the first communication path having a first uplink path and a first downlink path;
deciding, in the control plane, on an IP POP change to a second communication path in the user plane between the user equipment and a second IP POP having a second IP address, the second communication path having a second uplink path and a second downlink path; and
performing, in the control plane, the IP POP change from the first communication path to the second communication path, wherein the IP POP change is effected by:
preparing the second communication path;
switching from the first uplink path to the second uplink path, wherein premature use of the second downlink path is inhibited by firewall settings in the verification entity which are removed as part of the step of switching from the first downlink path to the second downlink path;
assigning the second IP address to the user equipment;
activating the second downlink path; and
releasing the first downlink path.
2. The method of claim 1 , wherein, for a temporary period after switching from the first uplink path to the second uplink path during which time the user equipment may be transmitting data packets bearing the first IP address, a filtering entity in the user plane is configured by a control plane command to re-route such uplink data packets to the first IP POP.
3. The method of claim 2 , wherein the filtering entity is configured by the control plane command to re-route uplink data packets to the first IP POP based on the uplink data packets carrying the first IP address.
4. The method of claim 2 , wherein the filtering entity is configured by the control plane command to re-route uplink data packets to the first IP POP based on the uplink data packets carrying a source IP address of the user equipment.
5. The method of claim 2 , wherein the filtering entity is configured by the control plane command to re-route uplink data packets to the first IP POP based on the uplink data packets having at least one header field with a specified content.
6. The method of claim 5 , wherein the header field is selected from the group consisting of: source IP address, destination IP address, source transport port, and destination transport port.
7. The method of claim 1 , wherein, for a temporary period after switching from the first uplink path to the second uplink path during which time the user equipment may be transmitting data packets bearing the first IP address, a verification entity in the user plane of the core network, which gates the data packets, is configured by a control plane command to allow such uplink data packets to pass.
8. The method of claim 1 , wherein the first communication path and the second communication path share a common radio bearer.
9. A core network component for managing Internet Protocol (IP) Point of Presence (POP) change for a user equipment in a communication architecture, the communication architecture having a user plane for packet data communication of user data and a control plane for controlling the packet data communication, the core network component comprising:
a control plane function unit, the control plane function unit comprising processing circuitry and memory containing instructions executable by the processing circuitry whereby the control plane function unit is operative to:
manage a first communication path in the user plane between a user equipment and a first IP POP having a first IP address, the first communication path having a first uplink path and a first downlink path;
decide, in the control plane, on an IP POP change to a second communication path in the user plane between the user equipment and a second IP POP having a second IP address, the second communication path having a second uplink path and a second downlink path; and
perform, in the control plane, the IP POP change from the first communication path to the second communication path, wherein the IP POP change is effected by:
preparing the second communication path;
switching from the first uplink path to the second uplink path, wherein premature use of the second downlink path is inhibited by firewall settings in the verification entity which are removed as part of the step of switching from the first downlink path to the second downlink path;
assigning the second IP address to the user equipment;
activating the second downlink path; and
releasing the first downlink path.
10. The core network component of claim 9 , wherein, for a temporary period after switching from the first uplink path to the second uplink path during which time the user equipment may be transmitting data packets bearing the first IP address, a filtering entity in the user plane is configured by a control plane command to re-route such uplink data packets to the first IP POP.
11. The core network component of claim 10 , wherein the filtering entity is configured by the control plane command to re-route uplink data packets to the first IP POP based on the uplink data packets carrying the first IP address.
12. The core network component of claim 10 , wherein the filtering entity is configured by the control plane command to re-route uplink data packets to the first IP POP based on the uplink data packets carrying a source IP address of the user equipment.
13. The core network component of claim 10 , wherein the filtering entity is configured by the control plane command to re-route uplink data packets to the first IP POP based on the uplink data packets having at least one header field with a specified contents.
14. The core network component of claim 13 , wherein the header field is selected from the group consisting of: source IP address, destination IP address, source transport port, and destination transport port.
15. The core network component of claim 9 , wherein, for a temporary period after switching from the first uplink path to the second uplink path during which time the user equipment may be transmitting data packets bearing the first IP address, a verification entity in the user plane of the core network, which gates the data packets, is configured by a control plane command to allow such uplink data packets to pass.
16. The core network component of claim 9 , wherein the first communication path and the second communication path share a common radio access bearer.