User-Plane Failover State Recovery for Policy and Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In mobile networking architectures with Control and User Plane Separation (CUPS), user-plane element failures lead to loss of metadata during deep packet inspection, resulting in under-charging or over-charging subscribers and degrading their experience due to the inability to classify ongoing flows accurately post-failure.
Innovation Solution
A method is provided to recover the last matched rule for ongoing flows by communicating restoration information, including flow identification and policy details, between the user-plane and control-plane elements using the Sx/N4 interface, ensuring consistent charging and policy application post-failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If user-plane element failover is implemented for high availability, then system reliability is improved, but metadata information is lost causing charging and policy errors
Solution Approach 1:
The patent applies preliminary action by storing restoration information (including flow identification and last matched rule) in the control-plane element before user-plane element failure occurs. This pre-stored information enables the failed user-plane element to recover its state without loss of metadata, resolving the contradiction between high availability through failover and preservation of critical information.
2Measurement precision
If deep packet inspection is performed for accurate charging, then measurement precision is improved, but service disruption occurs during failover
Solution Approach 1:
The patent applies copying by creating a replica of the user-plane element's state (restoration information including flow identification and last matched rule) and storing it in the control-plane element. When failover occurs, this copied state is rapidly restored, enabling deep packet inspection to resume immediately without service disruption, thus maintaining both measurement precision and minimizing time loss.
3Loss of information
If restoration information is stored in control-plane element, then information loss is prevented, but device complexity increases
Solution Approach 1:
The patent introduces the control-plane element as an intermediary that stores restoration information between user-plane elements. This intermediary approach prevents information loss during failover while distributing the complexity burden to a dedicated control component rather than increasing complexity within the user-plane elements themselves, thus resolving the contradiction between information preservation and device complexity.
Data Source
Figure 1
Figure 2A~2B
Figure 2C~2D
AI summary
Techniques that provide for the preservation of policy and charging for a subscriber following a user-plane element failover are described herein. In one embodiment, a method includes receiving, by a user-plane element, at least one data packet of a packet flow associated with a subscriber, wherein the at least one data packet is received after the user- plane element has recovered from a failure; determining, by the user-plane element, whether restoration information associated with the packet flow is stored at the user-plane element; and applying one or more policies to the packet flow based on a determination that the restoration information associated with the packet flow is stored at the user-plane element, wherein the restoration information comprises a rule associated with the packet flow.