Recovery of established emergency calls

An apparatus for re-establishing a call received at a public safety answering point comprising:

• a processor unit for executing instructions;
• and
• a memory for storing instructions, which when executed by the processor unit configure the apparatus to:
• receive a Session Initiation Protocol (SIP) call establishment request having an indication of a previously established emergency call to re-establish;
• search a call recovery queue for a previously received call establishment request having a matching indication for the previously established emergency call to re-establish;
• and
• bridge a call leg for the received call establishment request and a call leg for the previously received call establishment request having the matching indication for the previously established emergency call to re-establish when a match is found.

A system for re-establishing a call received at a public safety answering point comprising:

• an emergency call answer node comprising:
• a processor unit for executing instructions;
• and
• a memory for storing instructions, which when executed by the processor unit configure the apparatus to:
• receive a Session Initiation Protocol (SIP) call establishment request having an indication of a previously established emergency call to re-establish;
• search a call recovery queue for a previously received call establishment request having a matching indication for the previously established emergency call to re-establish;
• and
• bridge a call leg for the received call establishment request and a call leg for the previously received call establishment request having the matching indication for the previously established emergency call to re-establish when a match is found;
• a SIP proxy node comprising:
• a processor unit for executing instructions;
• and
• a memory for storing instructions, which when executed by the processor unit configure the SIP proxy node to:
• receive an emergency call initiation request;
• direct establishment of a call leg for the emergency call between an initial emergency call answer node and an emergency call operator workstation;
• direct establishment of a call leg for the emergency call between the initial emergency call answer node and an emergency call gateway;
• detect a failure of the initial emergency call answer node;
• and
• cause, with the SIP proxy, transmittal of one of the SIP call establishment request or the previously received call establishment request.