Thank you for answering.
K. Tsang wrote:Are your users be accessing a web app or desktop UI?
Users will access the system over a web app. However from my point of understanding this doesn't really makes a difference, because I don't want that on each local machine is a VPN client installed. Instead of this VPN means for me in this context a Site-to-Site VPN (or Gateway-to-Gateway-VPN).
K. Tsang wrote:Is a VPN server or the like needed? I let you do some research or ask your company support staff what is needed to support VPN.
What I found out so far is that there is no dedicated VPN server, instead in each connected network does a gateway (router) exists who is able to create and maintain this VPN tunnel. Additional effort and complexity can occurs if there is an overlapping between the new virtual network and the existing networks, and so extensive natting might be required.