What to read by phone?

Question

Telephony

In this question, rather than 0, but -1. There was a sharp need and, most importantly, a desire to understand the issues of telephony. I’ll make a reservation right away that I’ll beckon that this is a whole subject area and mastering it, not just in a swoop, but even for a long time and hard understanding it, is hard work, but I rather need to join in and understand the original terms. That is, in fact, I need something like a "road map", at least for the first time. Now I am working with phone numbers, checking their validity, so that there are no 1234 numbers (conditionally), etc. - I do all this with regulars, checking against arrays into which I entered the codes of operators and cities, but the general picture does not add up in my head.
Starting to search on the Internet, I saw that there are standards and a numbering plan, I also learned about the International Telecommunication Union, today I came across the terms MNC and MCC - as I understand it, that together they represent a unique number identifier.
These are the things I'm talking about - there are a lot of "scattered" (for a beginner) terms, I want to get a more general picture, at least an excursus. I know there is google, but then again, I'm looking for something more in the direction of a tutorial / book. I would be grateful for any advice on this matter.

Answer 1

B.S. Goldstein, A.V. Pinchuk, A.L. Sukhovitsky
IP-TELEPHONY
MOSCOW "RADIO AND COMMUNICATION"
2001
but in general you have nothing to do
, just take some twillio API and read tollfreeforwarding and see what's in the API