How would you design this network?

Hey guys,

​

Just wondering if someone can help me with this network design I gotta do. One of our remote offices in Europe is moving to a new location which is a service office. This new office has its own IT team and will not let us to install any NTU or move any of our services across. They do not let us to install access point and DHCP either. All we can get is dedicated internet bandwidth.

​

Current office, we have MPLS and ISDN but we're not going to have any of these in the new office.

​

Now what would you do in this situation to connect that office to the head office? We only have a few staff in that office so I was thinking of either establishing GRE tunnel to our head office or to use a VPN app on users PC. Then not quite sue what to do with Voice as ISDN is not available either.

​

I'd appreciate any feedback on this, thanks!