Decoupled Control and Data Plane Synchronization for IPsec Redundancy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current stateful geographic redundancy solutions for network elements like VPN gateways and ePDG that terminate IPsec tunnels face inefficiencies in recovering session states during network anomalies, leading to prolonged packet losses due to the need to synchronize both control and data plane information, which is resource-intensive and time-consuming.
Innovation Solution
The method decouples control-plane state synchronization from data-plane state synchronization, allowing the data-plane component to initiate packet processing immediately while control-plane information is stored and retrieved as needed, reducing recovery time by only engaging control-plane resources when necessary and storing state information in an external database.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If both control plane and data plane information are synchronized and programmed at standby nodes, then session state recovery is complete, but recovery time is extended and resource consumption increases
Solution Approach 1:
The patent segments the synchronization process into two independent parts: control plane state synchronization and data plane state synchronization. The data plane state is synchronized and made ready in advance, while control plane state is synchronized separately and can be restored independently. This segmentation allows the data plane to become operational quickly without waiting for control plane recovery, thus reducing overall recovery time while maintaining complete session state recovery.
Solution Approach 2:
The patent applies preliminary action by pre-synchronizing and pre-programming the data plane state information at standby nodes before any failure occurs. This includes pre-establishing encryption contexts, security associations, and other data plane processing elements. When a failure occurs, the standby node can immediately activate the pre-prepared data plane without waiting for control plane recovery, significantly reducing recovery time.
2Reliability
If both control plane and data plane functionality are programmed and activated at standby nodes, then session recovery is complete, but resource consumption for processors and memory increases
Solution Approach 1:
The patent segments resource allocation by separating control plane resources from data plane resources at standby nodes. Only data plane resources (encryption contexts, security associations, packet processing buffers) are pre-allocated and maintained in ready state. Control plane resources (session management logic, key management, routing decisions) are not pre-programmed but restored from synchronization data when needed. This segmentation dramatically reduces the resource footprint at standby nodes while maintaining complete recovery capability.
Solution Approach 2:
The patent treats control plane state information as disposable data that can be restored from external synchronization sources rather than maintaining expensive in-memory representations at standby nodes. The control plane state is externalized to synchronization databases or peer nodes, allowing standby nodes to use minimal resources for control plane functionality while maintaining full recovery capability through external state retrieval.
3Use of energy by moving object
If control plane information is stored externally, then standby node resource usage is reduced, but control plane recovery may be delayed
Solution Approach 1:
The patent ensures continuity of useful action by maintaining continuous synchronization of control plane state information from active to standby nodes through external databases or peer-to-peer synchronization mechanisms. This continuous synchronization ensures that when control plane recovery is needed, the state information is already available and can be rapidly loaded, minimizing recovery delay while keeping standby node resource usage low.
Solution Approach 2:
The patent introduces external synchronization databases or peer nodes as intermediaries for storing and exchanging control plane state information. These intermediaries handle the storage and retrieval burden, allowing standby nodes to access control plane state without maintaining large local resource allocations. The intermediary architecture enables efficient state restoration while keeping standby node resource consumption minimal.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Embodiments disclosed herein relate to systems and methods for separately managing control and data plan contexts for a secure connection during a standby node switchover scenario. Primary and standby nodes for a secure connection can both maintain a data plane context for a secure connection such as IPSec. In the event that the primary node becomes inactive, the standby node can immediately begin processing data plane traffic using the data plane context for the secure connection maintained at the standby node. Control plane information necessary for programming and activating a control plane context can be stored until needed. During a switchover, the standby node can retrieve the control plane information and activate the control plane context after it has begun processing the data plane traffic.