Emergency-Call Session Control Function (E-CSCF)
The E-CSCF receives the emergency session establishment request from a P-CSCF (in an IMS originating network) or the I-CSCF in an IMS-based NG9-1-1 Emergency Services Network), queries the LRF for routing information, and forwards the call request toward the appropriate PSAP or other emergency services network per the routing information.