Reactive Routing is an innovation in space networking by which unplanned changes in link performance are detected and analyzed, enabling automatic and immediate adjustments to the âcontact plansâ on which route computation in delay-tolerant networking (DTN) is based. These changes in contact planning will result in route revisions that will accurately reallocate traffic load to the revised transmission opportunities, improving network performance while reducing operations costs. Reactive Routing is only the first step toward the deployment of instrumented networks that monitor and examine their own operational experience and use the resulting insights to configure themselves for optimality. A key element of that future architecture will be software-defined radios that will support multiple wave form options, error correcting code options, and security features, and will interact with their networks to optimize spectrum use; antenna evolution will add beam steering, nulling, and frequency reconfiguration capabilities. These advanced software modems (ASMs) will incorporate control systems that manage the range of their capabilities to support network communication and science. Reactive Routing is the beginning of our initiative to bring the power of ASMs to networks built on the DTN Bundle Protocol (RFC 9171), culminating in autonomous cognitive networks that require little or no routine human management. Potential NASA Applications (Limit 1500 characters, approximately 150 words): Reactive Routing will enable a DTN BPv7 node to recompute routes and revise its bundle forwarding decisions automatically in responses to changes in the properties of communication links. It will improve link utilization, minimize throughput loss and management workload in all DTN-based networks supporting NASA missions. The immediate beneficiary will be LunaNet, but the benefit will be even greater for interplanetary missions where route revision in response to a link change would be delayed by at least one round-trip communication to Earth. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): The same performance improvements that will accrue to NASA space flight missions from adopting Reactive Routing will likewise benefit space flight operations mounted by all commercial space businesses and other national space agencies that use DTN for mission communications. Duration
