Blocking phone numbers with ip telephony?

Question

Android

He fell under the collectors (had the stupidity of becoming a confidant of one comrade).
Calls come regularly, 3-6 calls a day from different numbers. prefix 925, 926, 929, operator one.
It is useless to blacklist all numbers, as the collector himself said - we have IP telephony and there are a lot of numbers.
Question: Is it possible to block only their entire gateway? NOT by filters like 925 *, namely the source.
I'm a little familiar with JAVA, maybe there is a solution how to get data from an incoming call and extract valuable authentication data from it

Answer 1

maybe there is a solution how to get data from an incoming call and extract valuable data from it for authentication

There are third-party applications that take information about the caller's number into some kind of database. Look in the market, their darkness.
It is possible without third-party applications. If the blacklist is not suitable, then use the whitelist. All calls that come from numbers on the white list are considered legitimate, and all others will be dropped.

Answer 2

You can't do anything like this type of "scrape".
You can put, as advised above, any program like "anti-collector".
But such companies 1) do not wait for you to call them, and numbers (AON) can generate new ones every call. It's not legal, but a lot of people do it. This means that there will be no locks in the program. 2) you can look at the numbers - which telecom operator they belong to - and if all the numbers are of one telecom operator - block the entire pool. well, you, however, from this operator no one else will call.
I recommend:
1- check all the numbers that have called you on any site, such as "Never Call".
2- if all or most of the numbers are there - make a parser and write a program,
One moment, you describe numbers like "925, 926, 929", which means that they can take real, combat numbers in blocks of 50-100 pieces and change them every 1-2 months.