The Office of the Manager, National Communications Systems (OMNCS), tasked by directives from the White House to ensure that a survivable and enduring National Security and Emergency Preparedness (NS/EP) telecommunications capability is available during national emergencies has endorsed the development and adoption of a standard to support increased call completion capabilities for critical users. The High Probability of Completion (HPC) network capability would be applied during the call setup of NS/EP calls by providing for an identifier for those calls on the SS7 network protocol. This identifier would allow NS/EP to be recognized as they are transported across and between networks so that call completion improvement techniques could be applied by service providers to increase the probability of completion during periods of network congestion or damage.