Whenever you dial a telephone number that is located in the US, somehow your telephone company needs to be able to figure out which telephone company will complete the call. So for example suppose your cellular carrier is AT&T and you pick up your cell phone and dial a phone number. One of the first things that AT&T must do is somehow to figure out which telephone company is responsible for that phone number. Maybe that phone number is handled by Verizon. If so, then somehow AT&T needs to know to send your call to Verizon which will complete the telephone call.
How does your telephone company come to learn which telephone company is responsible for that phone number? Keep in mind that the person you are calling might “port” their cell phone number tomorrow from Verizon to T-Mobile. If so, then if you were to dial the same telephone number the day after tomorrow, your telephone company would need to know to send your call to T-Mobile instead of sending it to Verizon.
How does this work? And how does this relate to “number portability”? Continue reading “Companies that you never heard of that make telephone calls possible – part 1”
