Using the A Number Definition (DID - Direct Inward Dialing) as the LID

A valid telephone number (DID - in USA it is 10 digits), based on the North America Modern Plan (https://en.wikipedia.org/wiki/North_American_Numbering_Plan - Modern Plan) can be used to identify a device.

MX-ONE can send the A number in the “From” header of the SIP INVITE to the NG911 provider. The A number can be used to identify a device and its location if the NG911 provider database is configured for this.

Example:

InAttend client, directory number 220710 has a valid DID 4584220710.

Analog extension, directory number 220711 has a valid DID 4584220711.

Note that this setup is not recommended in a forking extensions scenario because the user can be logged in more than one place using the same extension. For example, a user has a phone logged in on their desk and they login in at another phone in a conference room. When an emergency call is established, the A number will be sent; however, the system does not know if that call was done from the desktop or the conference room. ELIN or MAC addresses can be used to solve this case.