OpenFlow Switch Packet Stacking for Controller Load Reduction
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Solution Overview
Problem
In open flow networks, continuous receipt of unregistered packets by switches leads to increased load on controllers due to repeated inquiry messages, causing network instability, and prevents packet transfer until flow entries are registered.
Innovation Solution
A load reducing system where switches stack unregistered packets and transfer them using packets with similar header data until the flow entry is registered, eliminating the need for repeated inquiry messages to the controller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If switches continuously send inquiry messages to the controller for unregistered packets, then the controller can register flow entries, but the load on the controller increases and network stability deteriorates
Solution Approach 1:
The switch performs preliminary actions by stacking unregistered packets locally and using similar-header packets for transfer before flow entry registration is complete. This prevents the need for continuous inquiry messages to the controller, reducing controller load while maintaining network stability through proactive packet handling.
2Manufacturing precision
If switches wait for flow entry registration before transferring packets, then routing accuracy is maintained, but packet transfer delay increases
Solution Approach 1:
The switch performs preliminary packet transfer using packets with similar header data before the formal flow entry registration is complete. This allows packet forwarding to begin in advance while maintaining routing accuracy through the use of comparable header information, thereby reducing packet transfer delay without sacrificing routing precision.
Solution Approach 2:
Packets with similar header data serve as intermediaries to enable packet transfer before the target flow entry is registered. These intermediary packets carry traffic forward using comparable routing information, bridging the gap between packet arrival and flow entry completion, thus reducing delay while preserving routing accuracy.
3Measurement precision
If the controller processes all inquiry messages from switches, then flow entries are registered accurately, but the processing time increases
Solution Approach 1:
The invention extracts the packet transfer function from the controller's processing queue by enabling switches to handle unregistered packets locally through stacking and similar-header packet transfer. This separation removes the time-consuming inquiry message processing from the controller's workload while maintaining flow entry registration accuracy through selective controller involvement.
Data Source
AI summary
An open flow network system is stabilized while reducing a load, by reducing inquiries of a flow entry to a controller about a flow in which a flow registration has not completed. Specifically, the controller registers the flow entry that defines a rule and an action to uniformly control packets as a flow in a flow table of a switch. When receiving a packet, the switch carries out an inquiry of the flow entry corresponding to the received packet to the controller, if the flow entry corresponding to the received packet is not registered on the flow table, and stacks the received packet. Also, the switch controls the transfer of the received packet which has the same header data as the stacked packet by using the stacked packet until the flow entry corresponding to the received packet is registered.