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Collaboration, Voice & AV · Advanced

Emergency Location Identification Number (ELIN)

A DID sent as the calling number on 911 calls so the PSAP can look up the caller's location and call back.

Definition

ELINs are DIDs registered in the PSAP ALI database with an ERL's address. When multiple calls come from the same ERL, multiple ELINs allow simultaneous callbacks. The emergency system maintains a temporary mapping from ELIN to the original caller so callbacks reach the right phone.

Example

Two simultaneous 911 calls from the same floor use ELINs 0300 and 0301 so both can be called back.

Exam tip

ELINs are reused per ERL; callbacks reach the original phone only for the mapping hold time.

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