Who is using which Voip provider. Advantages and disadvantages?

Question

SIP

What voip provider are you using?
What are the pros and cons?
I can single out Zadarma.com
+ stable work
+ adequate cost
+ a large number of lines
+ numbers of most cities and countries
- incomprehensible (inflated) cost of calls to Belarus
Actually, the last minus prompted me to look for another provider. But something didn't turn up.

Answer 1

When calling to Belarus, there will almost always be problems. I have tried different providers and all have this problem. This is due to local laws. The same Megafon quite often lands traffic bypassing the BTC, which affects the quality and, accordingly, the substitution of CallerID. Therefore, there are two options: 1) pay more and have a good connection with an immutable CallerID 2) pay little and get echo, delays, etc., as well as the CallerID of a local Belarusian operator