From the Introduction: "The Government Emergency Telecommunications Service (GETS) is an easy-to-use calling card program that provides authorized national security and emergency preparedness (NS/EP) users improved call completion on the public landline networks. It is a nationwide program providing authorized personnel priority calling during an emergency or crisis situation when the landline networks are congested and the probability of completing a call is reduced. GETS interoperates with selected government and private networks and services (FTS [Federal Technology Service] Networx; the Defense Switched Network; and the Diplomatic Telecommunications Service), and allows calls to or from international locations. The GETS card can be used with common telephone equipment, including standard desk sets, secure telephone equipment, facsimile, modems, and cellular and satellite phones."
U.S. Department of Homeland Security: https://www.dhs.gov/