This is done differently in different places of the world.
Here, the call center that takes all the emergency calls has A LOT of incoming phone numbers. Really, really long ones.
Whenever you make an emergency call, the phone operator is responsible for rerouting the emergency call number *to the long number that best describes the geographical location of the caller*.
After that, the emergency number routes the call to the nearest call centre (because there are quite a few of them, nation wide) where there is currently an operator available.
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