Written by PointBridge Senior Unified Communications Consultant and Microsoft MVP Jeff Schertz, this article describes how to correctly configure the Microsoft Office Communications Server Edge Server role on the Microsoft Windows Server 2008 platform when three or more network interfaces are used. In a basic Edge Server deployment, only two network interfaces are used (one is internal-facing and the other is external-facing). But when multiple interfaces are dedicated for external-facing communications, changes in the networking behavior of Windows Server 2008 R2 and Windows Server 2008 can limit proper traffic routing, preventing Web and A/V Conferencing features from working for external Microsoft Office Communicator clients.