SDN Switch Forwarding Table Update via Controller Version Sync
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Solution Overview
Problem
In Software Defined Networks (SDNs), interruptions between controllers and switches cause data forwarding interruptions due to the need for re-delivery of forwarding table entries, which is time-consuming and affects network performance, especially in large-scale networks.
Innovation Solution
An SDN setting method that involves sending a setting message with an update time to the switch during connection reestablishment, allowing the switch to update its forwarding table entries based on pre-stored entries from the controller, thereby minimizing data forwarding disruptions and improving network efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the controller re-delivers all forwarding table entries after reconnection, then forwarding table consistency is ensured, but data forwarding traffic is interrupted for a long time
Solution Approach 1:
The switch pre-stores backup forwarding table entries received from the controller before connection interruption. Upon reconnection, the switch can immediately restore forwarding capability using these pre-stored entries while consistency checks are performed in the background, eliminating the need to clear all entries and wait for complete re-delivery.
Solution Approach 2:
Instead of re-delivering all forwarding table entries completely, the controller only needs to deliver updated or missing entries. The switch compares its pre-stored entries with current controller entries and only applies necessary updates, reducing the reconnection restoration time while ensuring consistency.
2Reliability
If the controller clears all forwarding table entries and re-delivers them, then forwarding table consistency is achieved, but the complexity of the reconnection process increases
Solution Approach 1:
The patent extracts the essential function of ensuring forwarding table consistency from the complete re-delivery process. By using version numbers and selective updates, the system only performs the minimum necessary actions (comparing versions and updating specific entries) rather than the complete process of clearing and re-delivering all entries.
3Productivity
If the switch maintains pre-stored forwarding table entries during connection interruption, then data forwarding continues without interruption, but the risk of inconsistency with the controller increases
Solution Approach 1:
The switch uses version numbers as feedback mechanisms. When the controller sends forwarding table entries, it includes a version number. The switch compares this version number with its pre-stored entries to determine whether to update, ensuring consistency while maintaining continuous forwarding capability. This feedback loop allows the switch to synchronize with the controller only when necessary.
Data Source
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AI summary
The present disclosure discloses a software defined network (SDN) setting method, including: when it is detected that a connection to a controller is interrupted, forwarding data based on a pre-stored second forwarding table entry; after a connection reestablishment request is sent to the controller, receiving a setting message that is sent by the controller and that carries an update time; and when the connection to the switch is reestablished, updating, based on the update time, the second forwarding table entry according to a received first forwarding table entry from the controller. The present disclosure further discloses a controller, a switch, and a storage medium.