A network architecture includes a communication network that supports one or more network-based Virtual Private Networks (VPNs). The communication network includes a plurality of boundary routers that are connected by access links to CPE edge routers belonging to the one or more VPNs. To prevent traffic...http://www.google.co.uk/patents/US6778498?utm_source=gb-gplus-sharePatent US6778498 - Virtual private network (VPN)-aware customer premises equipment (CPE) edge router
