FE (Functional Element)

A set of software features that may be combined with hardware interfaces and operations on those interfaces to accomplish a defined task. Some Functional Elements may contain other Functional Elements.

Functional Elements in NG9-1-1
EIDO Indicates that the FE may send or receive EIDOs.
PSAP Indicates that the FE is typically part of a PSAP (without regard to physical location).
NGCS Indicates that the FE is typically part of NGCS (NG9-1-1 Core Services).

Functional Element	Description
ADR (Additional Data Repository)	A data storage facility for Additional Data. The ADR dereferences a URI passed in a Call-Info header field or PIDF-LO <provided-by> and returns an Additional Data object block. It replaces and deprecates the concept of CIDB previously defined in 08-003 v1.
BCF (Border Control Function)	The primary security function at the edge of the ESInet. Composed of Session Border controller for SIP and a traditional firewall for other protocols, plus some specialized NG9-1-1 functions.	PSAP NGCS
Bridge	Bridges (also referred to as "conference bridges" or "conference servers") are used in NG9-1-1 to transfer calls and conduct conferences. These have a SIP signaling interface to create and maintain conferences and media mixing capability. Conference Servers MUST be multimedia-capable (voice, video, text). In some deployments, all emergency calls are answered at a “Conference-Aware UA” which acts as a B2BUA until/unless a transfer or conference is needed, in which case it becomes the "Conference Bridge". When calls are "answered at a bridge" and when calls are forwarded by a bridge, the bridge generates an EIDO.	EIDO NGCS
Call Handling	The Call Handling Functional Element is concerned with the details of the management of calls. It handles all communication from the caller. From NENA/APCO-REQ-001.1.1-2016	EIDO PSAP
Collaboration	A Functional Element that provides for collaborative communications among agents, both within and between agencies. From NENA/APCO-REQ-001.1.1-2016	EIDO PSAP
Dispatch System	A Functional Element used to assign appropriate resources (emergency responders) to an incident, monitor the response and relay relevant information. Tracks and logs all transactions associated with the emergency response. From NENA/APCO-REQ-001.1.1-2016	EIDO PSAP
DNS (Domain Name Server)	All elements connected to the ESInet must have local DNS resolvers to translate hostnames they receive to IP addresses.
ECRF (Emergency Call Routing Function)	The routing database in NG9-1-1 which takes location (in civic or geo forms) and a “Service URN” and returns a route in the form of a URI to the next hop in the path the call should take. The ECRF is an instance of a LoST (RFC 5222) server.	NGCS
EIDO Endpoint FE	This is an FE used by entities outside of the PSAP and Core Services to exchange EIDOs with intra-ESInet entities.	EIDO
ESRP (Emergency Services Routing Proxy)	The ESRP is an instance of a SIP Proxy Server; an intermediary which routes calls. Note that an ESRP contains a Policy Routing Function, but the PRF is not a separate FE.	NGCS
GCS (Geocode Service)	An NG9-1-1 service providing geocoding and reverse-geocoding.	NGCS
IDX (Incident Data eXchange)	An EIDO coalescing function that provides a consolidated agency view of the current state of an incident by combining EIDOs generated by multiple constituent FEs within a PSAP. An IDX is usually the source of EIDOs for entities outside the PSAP. Another use is an element that combines EIDOs from multiple agencies working an incident to form an overall incident state. From NENA/APCO-REQ-001.1.1-2016	EIDO PSAP
IMR (Interactive Multimedia Response) System	An automatic multimedia call answering function that can play (multimedia) prompts, accept input (via DTMF or other forms) and record media. A multimedia form of IVR (Interactive Voice Response).	PSAP
Incident Record Handling	A Functional Element responsible for creation and/or handling of Incident records. NENA/APCO-REQ-001.1.1-2016	EIDO PSAP
LIS (Location Information Server)	A database that stores locations of endpoints. A LIS can provide Location-by-Reference, or Location-by-Value, and, if the latter, in geodetic or civic forms. A LIS can be queried by an endpoint for its own location, or, in some circumstances, by another entity for the location of an endpoint. The LIS is also the entity that provides the dereferencing service, exchanging a location reference for a location value.	NGCS
LNG (Legacy Network Gateway)	An NG9-1-1 Functional Element that provides an interface between an un-upgraded legacy origination network and the NGCS.  Note that an LNG contains a Location Interworking function (LIF), a Protocol Interworking Function (PIF) and an NG9-1-1 Interworking Function (NIF), but the LIF, PIF and NIF are not separate FEs.
Log Event Replicator	A LogEventReplicator has interfaces identical to LogEvent (NENA STA-010 Section 5.13.3). It can take a stream of LogEvents on its input port(s) and replicate them to each of its provisioned output ports. One of the output ports may be connected to the logging service, in which case all FEs that log would send their LogEvents to the replicator, which would copy them to the logging service and the other devices connected to the replicator. The replicator may be integrated into the logging service, may be stand-alone, or may be integrated into another FE.
Logging Service	An event and media logger. The Logging Service accepts log event records and media streams in a standardized form, stores them, and provides a standardized retrieval function for these records.	EIDO NGCS PSAP
LPG (Legacy PSAP Gateway)	An NG9-1-1 Functional Element which provides an interface between an ESInet and an un-upgraded PSAP. Note that an LPG contains a Location Interworking function (LIF), a Protocol Interworking Function (PIF) and an NG9-1-1 Interworking Function (NIF), but the LIF, PIF, and NIF are not separate FEs.	EIDO PSAP
LSRG (Legacy Selective Router Gateway)	The LSRG provides an interface between a 9-1-1 Selective Router and an ESInet, enabling calls to be routed and/or transferred between Legacy and NG networks. A tool for the transition process from Legacy 9-1-1 to NG9-1-1.	NGCS
LVF (Location Validation Function)	A functional element in an NGCS that is a LoST protocol server where civic location information is validated against the authoritative GIS database information.	NGCS
Management Console	A Functional Element that supports general management functions for the PSAP. It also sends and receives Discrepancy Reports on behalf of the PSAP. From NENA/APCO-REQ-001.1.1-2016	EIDO PSAP
Map Database Service	A database that stores mapping data that can be used to create a display for a call taker or dispatcher. Often used to provide maps for handling out of area calls, the Map Database Service can also be used locally to provide a single, uniform map display for all functional elements in a PSAP that need maps.
MCS (MSAG Conversion Service)	A web service providing conversion between NG9-1-1 PIDF-LO and Legacy MSAG data.	NGCS
MIS (Management Information System)	The MIS Functional Element provides reporting services based on data collected from FEs. From NENA/APCO-REQ-001.1.1-2016	EIDO PSAP
Policy Store	A database that holds policy rules.	NGCS PSAP
PSAP (Public Safety Answering Point)	An entity responsible for receiving 9-1-1 calls and processing those calls according to a specific operational policy. A PSAP is considered a single FE within the context of the NGCS, but of course, would be constructed of multiple FEs within the PSAP.	PSAP
RDS (Responder Data Services)	A Functional Element that enables near real-time wireless data transmissions between PSAPs and emergency responder devices. This includes transmitting dispatch information, creating new Incidents, updating active and closed Incidents. The Responder Data Services FE can support the transmission and receipt of media or a reference (i.e. URL) to that media. The RDS may include the "Radio Interface".  From NENA/APCO-REQ-001.1.1-2016	EIDO PSAP
RMS (Records Management System)	A database holding historical records of incidents and other PSAP records. From NENA/APCO-REQ-001.1.1-2016	EIDO PSAP
Service/Agency Locator	An Service/Agency Locator is a directory providing identification, contact and interface locations for all agencies on an ESInet. The Locator is searchable by name or location.	NGCS
Time Server	The ESInet must provide an NTP service for time-of-day information. The service may have a hardware clock, or may be synchronized to another NTP time service provided that there are sufficient backups so that if the ESInet is isolated from its time source, it can provide local time. Time accuracy must be within 1 ms of true time. Agencies may have their own time server, which may have a hardware clock if it is more accurate than syncing the server to the ESInet time server.