DPAS network control system, a real-time distributed self-healing network capability

The Digital Patch and Access System (DPAS), a digital cross-connect transmission system which is being deployed in the Defense Communications System, is discussed. Particular attention is given to the DPAS network control system (DNCS), a fully distributed network management system for the DPAS network. It is primarily designed to restore service to NxDS0 bandwidth circuits in order of restoration priority when the network is severely damaged, e.g., by acts of war, terrorists, or natural disasters. Preemption of lower-priority circuits to reroute higher-priority circuits is permitted. A four-node DPAS network was simulated with DNCS software installed on four computer systems. This distributed simulator environment was used to stress test the DNCS, varying timing and severity of the massive damage scenario events. A four-node DPAS testbed, with 12 internodal T1 facilities, was then built. The testbed was exercised under 50% internodal network damage to evaluate the survivability of the distributed control system under six control architecture damage scenarios