Inaccessibility of the site from some cities. How to check?

Question

Computer networks

Hello,
Tell me, plz, on the problem.
There is a site focused on the Russian-speaking audience. Hosted on VDS in firstvds, DC like webdc in Moscow.
A visitor from Russia (provider Rostelecom) complained that the site sometimes does not open due to a timeout. They began to understand:
- the site did not respond
- the tracer reaches the DC and stops there.
The site itself and the server are working normally. Checking from all hosts in host-tracker & ping-admin shows availability from all points.
The hoster began to freeze "send a bunch of mtr from the client to the server and from the server to the client." It is clear that visitors will not bathe with this.
Actually the question is: how to determine what percentage of visitors may not open the site? Is it worth it at all to worry or score? Could it be that, for example, 20% of visitors simply do not have a website available?

Answer 1

provider Rostelecom

As their user, I can say that routing violations are the norm for them. For example, on December 4, the trice went only to ya.ru, by the middle of the day other routes began to open, it still sausages.

Answer 2

https://ping-admin.ru/free_test/