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Emergency Call Routing Function


An Emergency Call Routing Function (ECRF) resolves the caller location and the requested service to an endpoint that the emergency call shall be forwarded to. The caller location can be provided either as geo-coordinates or as a civic address. The requested service is provided as a Service URN (e.g. urn:service:sos.police). An ECRF implements the Location to Service Translation (LoST) protocol as specified by the NG112 / NG-911 standards.


Usually, when referring to an ECRF, an ECRF Tree is meant. An ECRF Tree is an ECRF instance that resolves the endpoint for a requested service at a specific location within its specific coverage region. As an example, it resolves “urn:service:sos.police" at the location N48.2259 / E16.3767 to a specific IP address. The endpoint can be another ECRF or a Public Safety Answering Points (PSAPs). When the endpoint is another ECRF, the ECRF Tree can either respond with a redirect or use recursion (similar to DNS) to resolve the final endpoint for the request.


Forest Guide

The ECRF Forest Guide (FG) keeps track of multiple ECRF Trees and their coverage regions, so that a client does not need to know all the trees but only needs to contact the Forest Guide. Usually, the Forest Guide then responds with a redirect to the correct ECRF Tree. ECRF Trees are referenced by a specific NAPTR (Naming Authority Pointer) Resource Record that can be resolved to an IP address. The NAPTR mechanism, similar to DNS, enables the owner of a domain to freely change the ECRF's IP address, servers etc. without requiring a reconfiguration of the ECRF Forest Guide.


Next Generation Compliant

Both the ECRF Tree and ECRF Forest Guide follow the Next Generation standards.

In-Memory Caching

Optimized response times by using a sophisticated in-memory caching technology.

LoST Protocol

Information can be retrieved by using the LoST protocol and requests like findService, listService, etc.


Trace changes to the configuration, requests and responses for efficient monitoring and maintenance.

NAPTR Support

NAPTR support in ECRF Tree and ECRF Forest Guide, including recursion and loop detection.

Web App Administration

Easy administration and configuration of multiple tenants and access rights.

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