Virtual Switch Aging Flow Entry Recovery for OpenFlow Reliability
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Solution Overview
Problem
In OPENFLOW networks, when the secure channel between an OPENFLOW controller and an OPENFLOW switch becomes faulty, the deletion of flow entries due to aging mechanisms leads to the inability to forward subsequent data packets, resulting in a loss of data exchange functionality.
Innovation Solution
A data packet forwarding method and system that stores deleted aging flow entries in a virtual switch's aging flow table, allowing matching and re-delivery of these entries to the OPENFLOW switch when the secure channel is faulty, ensuring continued data packet forwarding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the OPENFLOW switch deletes flow entries according to the aging mechanism to save flow entry resources, then flow entry resources are saved, but when the secure channel is faulty, subsequently received data packets corresponding to these deleted flow entries cannot be forwarded, resulting in loss of data exchange function
Solution Approach 1:
The virtual switch FlowVisor intercepts and stores aging flow entries before they are deleted by the OPENFLOW switch. By performing this preliminary storage action, the system ensures that even when the secure channel is faulty and the switch deletes flow entries to save resources, the stored copies can be re-delivered to maintain forwarding capability, thus resolving the contradiction between resource savings and reliability
Solution Approach 2:
The virtual switch FlowVisor acts as an intermediary between the OPENFLOW controller and the OPENFLOW switch. It intercepts aging flow entries being deleted by the switch, stores them locally, and can re-deliver them when needed. This intermediary mechanism allows the system to delete flow entries for resource savings while maintaining the ability to restore them for reliability, resolving the technical contradiction
2Extent of automation
If the secure channel is used as the only channel between OPENFLOW controller and OPENFLOW switch for message exchange, then centralized control is achieved, but when the secure channel is faulty, the OPENFLOW switch cannot receive new flow entries or report PacketIn messages, causing complete control loss
Solution Approach 1:
The virtual switch FlowVisor serves as an intermediary communication channel between the OPENFLOW controller and the OPENFLOW switch. When the secure channel is faulty, the FlowVisor can intercept and forward control messages through alternative paths, ensuring that centralized control is maintained while bypassing the faulty secure channel, thus resolving the contradiction between centralized control and reliability
Data Source
AI summary
A data packet forwarding solution, which relates to the field of network transmission. A virtual switch in the solution saves a flow entry as an aging flow entry deleted from a flow table in a switch, and receives a reporting data packet generated according to a forwarding data packet when the forwarding data packet fails to match each flow entry in the flow table in the switch and a secure channel between the switch and the controller is faulty, delivers an aging flow entry matching the reporting data packet from an aging flow table to the switch, where the aging flow table includes one or more flow entries that are deleted as aging flow entries from a flow table in the switch.