Is it possible to implement such a scheme on a virtual PBX and from whom?

Question

ATS

We have a landline number in St. Petersburg. We plan to connect a landline number in Moscow and further 5-6 more numbers in other cities of Russia and further in other countries. Almost all numbers are connected via SIP.
Is it possible to "close" all numbers to a virtual PBX?
That is, so that customers can call the landline number of their city and their call would be transferred to the same virtual PBX. Total operators 1-2.
Thus, 2-n external numbers and 1-2 internal numbers are obtained (not for each external number, but in total) and one virtual PBX.
If the implementation of this scheme is not possible on a virtual PBX, then what options are possible?

Answer 1

Yes.
You buy numbers from your operators, set up virtual PBXs, register a connection to the 2nd PBX on each of the 2 phones.
Are there many operators' phones? But the PBX can say "All operators are busy, please wait ..."

Answer 2

IP-телефония: тут

Answer 3

Попробуйте VoxImplant - все что вы хотите, включая сами номера

Answer 4

Посмотрите у youmagic, помойму то что Вы описываете вполне реализуемо.