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About Emergency Location
The Emergency Location feature enables a Sangoma Phone Desktop Client user to hide the real CID number shown at the receiving end and instead use a custom DID number based on the chosen Location when an emergency number is dialed from the Desktop Client.
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NB: The option Additional Location Info is not used at present. This value is meant to be send along with the emergency call. But as of now asterisk doesn't have support for such a feature. So this will be implemented once the PIDF-LO feature in released in asterisk.