SDN Flow Policy Propagation via Control Packet
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In software-defined networks (SDNs), data packets may arrive out of order due to the lack of consistent handling by network nodes, as the SDN architecture does not guarantee that all nodes in a flow receive routing instructions before processing data packets.
Innovation Solution
A method where a start node initiates a flow by sending a route path request to an SDN controller, which determines the route path and communicates it only to the first forwarding node, which then generates and propagates a control packet along the route path to update the flow tables of subsequent nodes, ensuring instructions are received before any data packets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the SDN controller communicates route path information to all network nodes in the route path, then all nodes receive instructions before data packets, but control plane load increases and message complexity increases
Solution Approach 1:
The patent segments the control information distribution by having the SDN controller send route path information only to the first network node, which then segments the propagation task by forwarding to subsequent nodes. This divides the control plane load across multiple data plane nodes rather than concentrating it all in the controller.
Solution Approach 2:
The first network node acts as an intermediary that receives control information from the SDN controller and mediates its distribution to subsequent network nodes. This intermediary approach reduces direct control plane communications while ensuring reliable propagation of flow instructions.
2Reliability
If the SDN controller communicates route path information to all network nodes in the route path, then all nodes receive instructions before data packets, but the number of control communications increases
Solution Approach 1:
The control communication process is segmented into one control plane communication from the SDN controller to the first node, followed by data plane communications from the first node to subsequent nodes. This segmentation reduces the number of control plane communications while maintaining reliable instruction propagation.
Solution Approach 2:
The first network node serves as an intermediary that converts one control plane communication into multiple data plane communications, reducing the overall number of control plane messages while ensuring all nodes receive necessary instructions before data packet transmission.
3Productivity
If data packets are sent before route path information is communicated to all nodes, then data transmission can begin immediately, but data packets may arrive out of order
Solution Approach 1:
The system performs preliminary action by ensuring route path information is propagated to all network nodes before data packets are transmitted. The first node receives control information, updates its flow table, and propagates instructions to subsequent nodes before allowing data packet forwarding, ensuring proper ordering while maintaining efficiency.
4Adaptability or versatility
If the SDN controller directly manages all network nodes, then routing decisions are centralized and adaptable, but control plane load and communication overhead increase
Solution Approach 1:
The centralized control capability is segmented by having the SDN controller manage only the first network node for control information distribution, while subsequent nodes autonomously receive and propagate instructions through data plane communications. This maintains centralized adaptability while distributing control plane load.
Solution Approach 2:
The first network node acts as an intermediary between the SDN controller and subsequent nodes, allowing the controller to maintain centralized adaptability through programmable control while reducing direct control plane communications. The intermediary propagates control decisions through the data plane, reducing overall control plane load.
Data Source
AI summary
Propagating a flow policy within a software defined network (SDN) includes sending a route path request for a flow from a first forwarding node to an SDN controller of the SDN, receiving route path information specifying a route path for the flow from the SDN controller, and generating, using a processor of the first forwarding node, a control packet including the route path. The control packet is communicated from the first forwarding node to a second forwarding node.