FAQ WebAppYes. The Database server and web server can be on separate physical systems. Systems can be separated by a firewall. A single port of communication must be opened between database server and web server. Communication between the database server and web server uses XML over HTTP. The connection can be an encrypted channel (VPN, etc). The XML over HTTP communication is clear text and easy to firewall (unlike CORBA, ODBC or proprietary binary protocols). The EMu software implements it's own security on the software layer (in addition to encryption and firewalling). This includes "trusted host" ACL's and the requirement for XML database connections to use an authentication token.