Delay-Tolerant Network Management: The Definition and Exchange of Infrastructure Information in High Delay Environments
Edward J. Birrane, Hans Kruse · Infotech@Aerospace 2011 · 2011
A delay-tolerant network (DTN) may comprise nodes whose information exchange is delayed either by signal propagation delay or frequent link disruption. Nodes on the far side of these high-latency links must still be managed. However, these nodes do not support closed-loop control with a human-in-the-loop network operations center. Terrestrial network management (NM) applications such as the Simple Network Management Protocol (SNMP) achieve closed-loop control through the use of pull mechanisms to request finegrained performance information and apply node configurations. Implementing these mechanisms over DTNs requires a level of bandwidth utilization and round-trip delay that may not be sufficiently reactive to apply corrective action before catastrophic network failure. Open-loop network management uses a push model inspired by the implementation of spacecraft telemetry systems. A push model requires the implementation of automation and fault protection at nodes communicating over high-latency links. This paper redefines the roles and responsibilities of DTN NM, presents state information to be captured for an emerging DTN data protocol, identifies key characteristics of a successful NM protocol, and discusses how these protocols interact with counterparts in low-latency networks. This paper concludes that a data exchange model in high-delay networks must rely upon the intelligent push of relevant node information. The intelligent push of data must be driven by missionspecific configuration and support fault protection. Such systems push the state of the art for management applications, but have precedent in spacecraft on-board systems and other embedded, real-time, mission-critical applications operating without human intervention.