Media for Making incoming calls also ring a phone line in remote office?

Making incoming calls also ring a phone line in remote office?

Hello

We are about to have a second office, in a different city, and would like that, when a call comes in on the number that customers are used to dial, it will also ring a phone in the remote office, so that whoever is available picks up the call. In other words, I'm not looking for call rerouting.

Does someone know whether this feature is available from telco's or ISP's, or do I have to get some miniPBX to make this happen?

Thank you.