How to organize an office PBX?

Question

Telephony

Hello! The question may not be entirely correct, you need to organize the transfer of calls from one number to another (the numbers are different). How to organize it? Googling led me to instructions for a full-blown deployment of a PBX. What should the connection diagram look like to organize such a translation, while maintaining different numbers? How should the connection diagram look like if you use one number, and already transfer to internal numbers from one?
PS offer to use the provider's services do not offer!

Answer 1

The scheme is always approximately the same:
- at the input you have an analog line with a number (numbers) - you program an analog PBX to receive an incoming call to 1 internal number (for example, a secretary who will transfer to internal numbers).
- the same, but you have SIP - here you install / configure softf for call routing (FreeSwitch, Asterisk, Oktell, Kazoo).
- you have an analog line, but SIP phones work - install an FXO gateway, then everything is as above.