What services are there for organizing telephone conferences (teleconferences) with support for numbers for Russia and Belarus?

Question

Telephony

We are looking for a service that allows organizing a teleconference with the ability for participants from the Russian Federation and Belarus to call local numbers or 800 numbers free for the caller.
I would like to have standard features:
- entrance to the conference by pin code
- use both by phone and computer
- no sound advertising and announcement of the service when entering the conference
- reasonable cost at the level of Webex, Gotomeeting
The ability to present the screen is not required.

Answer 1

Ready not prompt.
If in Belarus 800 can be picked up via SIP or E1, it is easier and cheaper to make such a conference on your own.

Answer 2

It's easier then to have two free numbers - one in Belarus and one in Russia and connect via SIP

Answer 3

8 800 and free numbers in each country are different, you have to buy numbers here and there. In Belarus, due to the monopoly of Beltelecom, open external SIP traffic seems to be prohibited.