Implementing an Emergency Telecommunications Service (ETS) for Real-Time Services in the Internet Protocol Suite

RFCs 3689 and 3690 detail requirements for an Emergency Telecommunications Service (ETS), of which an Internet Emergency Preparedness Service (IEPS) would be a part. Some of these types of services require call preemption; others require call queuing or other mechanisms. IEPS requires a Call Admission Control (CAC) procedure and a Per Hop Behavior (PHB) for the data that meet the needs of this architecture. Such a CAC procedure and PHB is appropriate to any service that might use H.323 or SIP to set up real-time sessions. The key requirement is to guarantee an elevated probability of call completion to an authorized user in time of crisis. This document primarily discusses supporting ETS in the context of the US Government and NATO, because it focuses on the Multi-Level Precedence and Preemption (MLPP) and Government Emergency Telecommunication Service (GETS) standards. The architectures described here are applicable beyond these organizations. Baker & Polk Informational [Page 1] RFC 4542 ETS in an IP Network May 2006