SDN Controller Packet-In Rate Management
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Solution Overview
Problem
Software-defined network (SDN) devices experience control plane overload due to a high volume of unmatched packets, which overburdens the control plane processor and disrupts network operations, as it spends excessive resources generating packet-in messages for the SDN controller.
Innovation Solution
An SDN controller counts packet-in messages and classifies them into match field buckets; if the rate exceeds a threshold, it generates a filter flow rule to divert matching packets to a non-SDN forwarding pipeline, reducing the load on the control plane by sending the filter flow rule to the network device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the SDN forwarding pipeline processes all unmatched packets through the control plane, then the network device can dynamically adapt to new traffic flows and policies, but the control plane processor becomes overloaded and network operations are disrupted
Solution Approach 1:
The patent segments the packet processing function by dividing packets into two categories: those requiring SDN controller involvement and those that can be handled by local forwarding rules. The filter flow rule mechanism creates a segmentation point where packets matching the filter rule are diverted to the non-SDN pipeline, while other packets continue through the SDN pipeline for dynamic processing.
Solution Approach 2:
The patent extracts the high-volume, predictable traffic patterns from the control plane processing load by identifying and filtering them out using match field buckets. This extraction removes the harmful burden of processing excessive packet-in messages while preserving the control plane's ability to handle truly dynamic and unpredictable traffic flows.
2Reliability
If the control plane processor handles a high volume of packet-in messages, then comprehensive network policy enforcement is achieved, but processing time increases and network speed decreases
Solution Approach 1:
The patent applies preliminary action by pre-configuring filter flow rules based on analyzed traffic patterns before the actual high-volume traffic arrives. The SDN controller proactively identifies traffic flows that can be filtered and installs filter rules in advance, so when the traffic arrives, it is automatically diverted without requiring real-time control plane intervention for each packet.
Solution Approach 2:
The patent implements partial action by selectively applying filter flow rules only to specific traffic patterns that match predetermined criteria, rather than processing all packets through the control plane. This partial filtering approach is sufficient to reduce control plane overload while maintaining complete policy enforcement for the remaining traffic that requires SDN processing.
3Productivity
If filter flow rules are generated to divert packets to non-SDN pipeline, then control plane load is reduced, but the complexity of managing dual forwarding pipelines increases
Solution Approach 1:
The patent uses match field buckets as an intermediary mechanism that simplifies the management of dual forwarding pipelines. The buckets serve as a classification layer that automatically categorizes packets based on predefined criteria, making it easier to manage the complexity by providing a structured interface between the SDN and non-SDN pipelines without requiring complex manual configuration or management.
Data Source
AI summary
Example implementations relate to reducing control plane overload of a network device. In an example, a non-transitory computer-readable storage medium may store instructions that, when executed by a processor of an SDN controller, cause the SDN controller to track packet-in messages received from a controlled switch and, if a rate of packet-in messages received from the controlled switch exceeds a threshold, send a flow rule to the controlled switch to divert a subset of unmatched flows to a non-SDN forwarding pipeline of the controlled switch.