Preservation of policy and charging for a subscriber following a user-plane element failover

1. A method comprising:

obtaining, by a user-plane element, restoration information for one or more packet flows from a control-plane element, wherein the restoration information for the one or more packet flows is obtained via a session establishment request message obtained from the control-plane element;

receiving, by the user-plane element, at least one data packet of a particular packet flow associated with a subscriber, wherein the at least one data packet is received following a failure of the user-plane element or another user-plane element that previously handled the particular packet flow associated with the subscriber;

determining, by the user-plane element, whether particular restoration information associated with the particular packet flow is stored at the user-plane element; and

in response to determining that the particular restoration information associated with the packet flow is stored at the user-plane element, applying one or more policies to the particular packet flow, wherein the restoration information comprises a last matched rule for the particular packet flow that was determined prior to the failure of the user-plane element or the another user-plane element that previously handled the particular packet flow associated with the subscriber.

2. The method of claim 1 , further comprising:

in response to determining that the restoration information associated with the particular packet flow is not stored at the user-plane element, determining a classification for the particular packet flow, wherein the classification is based on rule information stored on the user-plane element.

3. The method of claim 1 , further comprising:

prior to receiving the at least one data packet, determining a classification for the particular packet flow by the user-plane element or the another user-plane element that previously handled the particular packet flow associated with the subscriber; and

communicating the restoration information to the control-plane element.

4. The method of claim 3 , wherein the restoration information is included in a Packet Forwarding Control Protocol Session Report message communicated to the control-plane element.

5. The method of claim 3 , wherein the restoration information comprises:

flow information identifying one or more of: a source address, a source port, a destination address, a destination port, a protocol, or a flow identifier associated with the particular packet flow; and

at least one of: a rule name or a rule identifier that indicates the last matched rule associated with the particular packet flow; an application identifier that indicates an application associated with the particular packet flow; or an application instance identifier that is associated with the application.

6. The method of claim 3 , wherein the communicating is performed based on at least one of:

determining that the particular packet flow is active for more than a threshold time;

determining that the classification for the particular packet flow corresponds to a particular flow type for which the restoration information is to be communicated to the control-plane element; and

determining that the particular packet flow is less than a maximum number of packet flows that can be restored on the user-plane element.

7. The method of claim 1 , further comprising:

determining, by the user-plane element, a termination or deletion of the particular packet flow associated with the subscriber; and

sending a communication to the control-plane element that indicates that restoration information associated with the particular packet flow is to be removed at the control-plane element.

8. The method of claim 1 , further comprising:

determining, by the user-plane element, an updated classification for the particular packet flow associated with the subscriber; and

sending a communication to the control-plane element to update the restoration information associated with the particular packet flow.

9. The method of claim 1 , wherein the session establishment request message is a Packet Forwarding Control Protocol Session Establishment Request message.

10. The method of claim 1 , wherein the restoration information is included within a restore flow grouped information element (IE) within the session establishment request message and the restore flow grouped IE comprises a flow information IE including information identifying the particular packet flow and a rule matched IE indicating the last matched rule.

11. One or more non-transitory computer readable storage media encoded with instructions that, when executed by a processor, cause the processor to perform operations, comprising:

obtaining, by a user-plane element, restoration information for one or more packet flows from a control-plane element, wherein the restoration information for the one or more packet flows is obtained via a session establishment request message obtained from the control-plane element;

receiving, by the user-plane element, at least one data packet of a particular packet flow associated with a subscriber, wherein the at least one data packet is received following a failure of the user-plane element or another user-plane element that previously handled the particular packet flow associated with the subscriber;

determining, by the user-plane element, whether particular restoration information associated with the particular packet flow is stored at the user-plane element; and

in response to determining that the particular restoration information associated with the packet flow is stored at the user-plane element, applying one or more policies to the particular packet flow, wherein the restoration information comprises a last matched rule for the particular packet flow that was determined prior to the failure of the user-plane element or the another user-plane element that previously handled the particular packet flow associated with the subscriber.

12. The media of claim 11 , wherein the execution causes the processor to perform further operations, comprising:

in response to determining that the restoration information associated with the particular packet flow is not stored at the user-plane element, determining a classification for the particular packet flow, wherein the classification is based on rule information stored on the user-plane element.

13. The media of claim 11 , wherein the execution causes the processor to perform further operations, comprising:

prior to receiving the at least one data packet, determining a classification for the particular packet flow by the user-plane element or the another user-plane element that previously handled the particular packet flow associated with the subscriber; and

communicating the restoration information to the control-plane element.

14. The media of claim 13 , wherein the restoration information is included in a Packet Forwarding Control Protocol Session Report message communicated to the control-plane element.

15. The media of claim 11 , wherein the execution causes the processor to perform further operations, comprising:

determining, by the user-plane element, a termination or deletion of the particular packet flow associated with the subscriber; and

sending a communication to the control-plane element that indicates that restoration information associated with the particular packet flow is to be removed at the control-plane element.

16. The media of claim 11 , wherein the execution causes the processor to perform further operations, comprising:

determining, by the user-plane element, an updated classification for the particular packet flow associated with the subscriber; and

sending a communication to the control-plane element to update the restoration information associated with the particular packet flow.

17. A user-plane element comprising:

at least one memory element for storing data; and

at least one processor for executing instructions associated with the data, wherein executing the instructions causes the user-plane element to perform operations, comprising:

obtaining, by the user-plane element, restoration information for one or more packet flows from a control-plane element, wherein the restoration information for the one or more packet flows is obtained via a session establishment request message obtained from the control-plane element;

receiving, by the user-plane element, at least one data packet of a particular packet flow associated with a subscriber, wherein the at least one data packet is received following a failure of the user-plane element or another user-plane element that previously handled the particular packet flow associated with the subscriber;

determining, by the user-plane element, whether particular restoration information associated with the particular packet flow is stored at the user-plane element; and

in response to determining that the particular restoration information associated with the packet flow is stored at the user-plane element, applying one or more policies to the packet flow, wherein the restoration information comprises a last matched rule for the particular packet flow that was determined prior to the failure of the user-plane element or the another user-plane element that previously handled the particular packet flow associated with the subscriber.

18. The user-plane element of claim 17 , wherein executing the instructions causes the user-plane element to perform further operations, comprising:

in response to determining that the restoration information associated with the particular packet flow is not stored at the user-plane element, determining a classification for the particular packet flow, wherein the classification is based on rule information stored on the user-plane element.

19. The user-plane element of claim 17 , wherein the restoration information comprises:

flow information identifying one or more of: a source address, a source port, a destination address, a destination port, a protocol, or a flow identifier associated with the particular packet flow; and

at least one of: a rule name or a rule identifier that indicates the last matched rule associated with the particular packet flow; an application identifier that indicates an application associated with the particular packet flow; or an application instance identifier that is associated with the application.

20. The user-plane element of claim 17 , wherein executing the instructions causes the user-plane element to perform further operations, comprising:

determining, by the user-plane element, an updated classification for the particular packet flow associated with the subscriber; and

sending a communication to the control-plane element to update the restoration information associated with the particular packet flow.