SDN Controller Flow Table Indexing for OpenFlow Switch Overhead Reduction
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Solution Overview
Problem
The existing OpenFlow technology faces high overheads and congestion risks in the control channel due to the delivery of complete standard flow table entries by the SDN controller to the OpenFlow switch, leading to increased network processing resource consumption.
Innovation Solution
A method where the SDN controller generates a flow table entry with an index of an actual value, rather than the actual value, which is sent to the OpenFlow switch, allowing the switch to obtain the actual value based on the index, thereby reducing data volume and resource consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the SDN controller delivers complete standard flow table entries to the OpenFlow switch, then the flow table entries contain all necessary information for packet forwarding, but the control channel overhead increases and congestion risk increases
Solution Approach 1:
The patent extracts only the essential index information from complete flow table entries and transmits them through the control channel. The SDN controller generates flow table entries containing indexes that reference actual values stored locally at the OpenFlow switch, thereby extracting and removing redundant data from the control channel transmission while maintaining access to complete information at the switch.
Solution Approach 2:
The patent creates a simplified copy of the flow table entry that contains only indexes rather than complete data. These index-based copies are transmitted through the control channel, while the actual complete values are maintained as separate copies at the OpenFlow switch, allowing the system to work with lightweight representations during control plane communication.
2Reliability
If the SDN controller delivers complete standard flow table entries to the OpenFlow switch, then the flow table entries contain all necessary information for packet forwarding, but the network processing resources of both the SDN controller and the OpenFlow switch are occupied
Solution Approach 1:
The patent extracts only the essential index information from complete flow table entries and transmits them through the control channel. The SDN controller generates flow table entries containing indexes that reference actual values stored locally at the OpenFlow switch, thereby extracting and removing redundant data from the control channel transmission while maintaining access to complete information at the switch.
Solution Approach 2:
Instead of the conventional approach where the controller sends complete flow table entries and the switch processes them, the patent inverts the process by having the switch maintain local copies of actual values and only receiving indexes from the controller. This inversion shifts the processing burden from the control channel to the data plane, reducing controller and switch resource consumption during flow table updates.
3Quantity of substance
If indexes are used instead of actual values in flow table entries, then the data volume of flow table entries is reduced, but the switch needs to obtain actual values based on indexes
Solution Approach 1:
The patent applies preliminary action by having the OpenFlow switch pre-load and store actual flow table values in its local memory before receiving index-based flow table entries from the SDN controller. This advance preparation eliminates the need for complex real-time resolution processes, as the switch simply needs to perform a straightforward lookup of pre-stored values using the received indexes.
Data Source
AI summary
A flow table management method, devices, and systems. The flow table management method includes: generating, by a software defined network controller, a first flow table entry, where a first field set in the first flow table entry carries an index of an actual value in the first field set, and the first field set includes N fields; and sending, by the software defined network controller, an OpenFlow protocol message to an OpenFlow switch, where the OpenFlow protocol message carries the first flow table entry. The technical solution in the embodiments of the present invention helps reduce a data volume of flow table entries delivered by an SDN controller to an OpenFlow switch, thereby reducing overheads of a control channel to reduce a congestion risk of the control channel, and reducing occupied network processing resources of the SDN controller and the OpenFlow switch to deliver the flow table entries.