ECRF (Emergency Call Routing Function)

A functional element in an ESInet which is a LoST protocol server where location information (either civic address or geo-coordinates) and a Service URN serve as input to a mapping function that returns a URI used to route an emergency call toward the appropriate PSAP for the caller's location or towards a responder agency.
 * External ECRF: An ECRF instance that resides outside of an ESInet instance.
 * Internal ECRF: An ECRF instance that resides within and is only accessible from an ESInet instance.