SDN Control-to-Data Interfaces for Delay-Tolerant Topology Changes
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Solution Overview
Problem
Software-defined networks (SDNs) in aerospace and mobile networks face challenges with unreliable, high-latency links, which traditional control-to-data-plane interfaces (CDPIs) do not support, leading to frequent disruptions and difficulties in managing network topology reconfigurations due to node movement.
Innovation Solution
An SDN controller sends control messages with instructions for network nodes to modify physical topology parameters, such as aiming steerable wireless transceivers and adjusting transmitter settings, along with scheduling information to execute these changes at specified future times, ensuring confirmation before updating routing information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional CDPI is used in SDN, then control messages can be transmitted to network nodes, but the system cannot tolerate delays and disruptions caused by unreliable links in mobile networks
Solution Approach 1:
The patent applies preliminary action by having network nodes pre-execute topology modifications at scheduled future times before disruptions occur. The SDN controller schedules control messages with future execution timestamps, allowing nodes to autonomously perform topology changes and routing updates in advance, thereby tolerating subsequent delays and disruptions without requiring complex real-time control message handling during disruptions.
2Reliability
If frequent topology reconfigurations are performed to handle node movement, then network connectivity is maintained, but control message delays cause nodes to become stranded
Solution Approach 1:
The system performs topology modifications and routing information updates in advance by scheduling control message execution at future timestamps. Nodes autonomously execute these pre-scheduled actions without waiting for real-time control messages, eliminating the time loss associated with control message delays during frequent topology reconfigurations.
Solution Approach 2:
Network nodes autonomously execute topology modifications and routing updates based on pre-scheduled control messages without requiring continuous control plane communication. This self-service capability allows nodes to maintain connectivity during control message delays, as they can independently perform necessary reconfigurations based on previously received instructions.
3Speed
If control messages are sent immediately for topology changes, then rapid reconfiguration is achieved, but disruptions during message transmission cause execution failures
Solution Approach 1:
The SDN controller sends control messages with future execution timestamps, allowing topology modifications to be scheduled and executed at predetermined times. This preliminary scheduling ensures that reconfiguration actions are prepared in advance but executed only when conditions are favorable, maintaining rapid reconfiguration capability while avoiding execution during disruptive periods.
Solution Approach 2:
The system dynamically adjusts the execution timing of topology modifications by scheduling control messages with future timestamps based on predicted network conditions. This dynamic timing allows the system to optimize between rapid reconfiguration and execution reliability, selecting optimal moments for actual topology changes while maintaining the capability for fast response when needed.
Data Source
AI summary
This disclosure provides systems and methods for improving tolerance of delay and disruption of a control-to-data-plane interface (CDPI) in a software-defined network. A system can include a plurality of moving nodes and an SDN controller communicatively coupled to the plurality of moving nodes. The SDN controller can be configured to send a first control message to a first moving node of the plurality of moving nodes according to a CDPI protocol. The first control message can include instructions for the first moving node to execute a modification of a physical network topology parameter. The SDN controller also can be configured to send a second control message to the first moving node according to the CDPI protocol. The second control message can include instructions for the first moving node to modify routing information stored by the first node based on the modification of the physical network topology parameter.