twowindsbear wrote:
It has to do with the number of phones & phone customers that the phone system can handle. A typical phone exchange can have 10,000 phone numbers - xxx-0000 to xxx-9999. There's a limit on how many phones can actually make a call at any one time. I think that number is 100. So, 100 people are talking, customer 101 won't even get a dial tone until some else ends their call. At some point the telco will add another exchange to keep their customers happy. I imagine newer telco systems can have more customers making calls at the same time. In theory, a 10 digit phone number allows for 9,999,999,999 different phone numbers. Many of those numbers aren't available, though. For example, in the US you can't have a 911 area code or exchange number. Same with 811, 411 and other similar numbers. I won't even go into adding a country code to this mix.
It has to do with the number of phones & phone... (
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You are absolutely right....
Back in the 50's I was in the U.S Air Force and my job was to do the maintenance on Dial Telephone Central Office Equipment. I put my 4 years into it and after 4 years my hitch was up and I got out.
We even had Operator Switch Boards then. I really enjoyed the work.