Hello. Im writing from Italy (...sorry for my English). A premise: I do not know if the topic of this question has been previously and widely discussed. If I so, then please indicrarmi direct references and where to find all relevant information. So. In FARM, we have a forest with two domains and 4 domain controller (Windows Server 2003 R2). We need to set up an office abroad as soon as possible. In this office will work both those already defined in our AD is probably not going to be people who; the network connectivity for the office will be based most likely on a wild VPN site-to-site and a firewall is expected. I wish I had the advice on the safest possible structure that exploits the existing authentication mechanism and that, if the network connection goes KO, allowing those who are still in that office to continue working. With regard to the hierarchy between the root domain and the office: trust or noly federation? Thanks