E-CSCF (Emergency Call Session Control Function)

Also known as: Emergency CSCF, Emergency Call Session Control Function

E-CSCF is a specialised CSCF that handles IMS emergency sessions. It receives emergency SIP INVITEs from the P-CSCF, retrieves or validates location information, selects an appropriate PSAP route via a Location Retrieval Function and BGCF, and enforces emergency-specific policies. Security considerations include preventing spoofed emergency identities, ensuring anonymous emergency calls still meet regulatory location requirements, and resisting denial-of-service targeting PSAP routing.

Categories: Internet and Routing

E-CSCF in context

Telecom networks depend on Internet-style routing (BGP, DNS, MPLS) for interconnect. Route hijacks and DNS abuse can degrade or intercept signaling, which is why RPKI and DNSSEC are now standard hardening for carrier networks.

To place E-CSCF in the wider telecom-security picture, review 3G, 3GPP, A5/1, A5/2, A5/3 and ASN — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.