Emergency Nurse Practitioner (ENP) Practice Test 2025 – 400 Free Practice Questions to Pass the Exam

The SIP proxy server is responsible for routing communication between devices in a network using the Session Initiation Protocol (SIP). In the ESInet, the SIP proxy server, or Emergency Services Routing Proxy (ESRP), has the additional function of selecting the next hop routing server based on location and policy. Therefore, options A, B, and C (BSM, ECRF, and ESRK) are incorrect as they do not function as SIP proxy servers within the ESInet. Option A (BSM) is an acronym for Basic Service Manager, a component of the IP Multimedia Subsystem (IMS). Option B (ECRF) is an acronym for Emergency Call Routing Function, which provides routing information for emergency calls but does not function as a SIP proxy server. Option C (ESRK) is an acronym for Emergency Services Routing Key, which is a function of NG9-1-1 networks that provides routing information for emergency calls. None of these options have the same functions as the SIP proxy server within the ESInet.