What is the best way to organize a network between several offices?

Question

Computer networks

Good afternoon, there are 2-3 offices (maybe more), they bought very expensive software for the company that is installed only on Windows, it works on a local network, I allocated a separate laptop for this software and everything would be fine, but you need to use the software in the rest offices
, I don’t quite understand the vpn principle so far (apparently it’s the only one I need), who will tell you how to set everything up correctly?
ps
1) I have a router (asus RT-N12+) on the network with a laptop. It has a built-in PPTP VPN server function, I don’t know what it is and whether it will help if the server is only here, how to deal with clients, etc.
2) what routers in other offices I don’t know yet
3) I have an ubuntu server on the same network with a router and software, maybe this will help somehow

Answer 1

hire someone to do it

Answer 2

vpn is a must. Asus RT-N12 is rather weak in my opinion, but for the first time it will be enough (I would stick microtics everywhere). If the hardware key is Snetinel(hasp) with the software, then it is better to stick it into the server, because it is more reliable this way.
If the software is tied to the hardware, then it's better to install a non-virtual one - set it up and back it up. And to it already on RDP to be connected. Although for the first time you can leave it on the laptop.
Vobshchem begin with VPN - that the laptop freely responded from other offices to the internal address.

Answer 3

Good afternoon.
If you have ubuntu you can try openvpn.
and I advise you to change your router to some kind of cisco or mikrotik.