A service provider's routers (PE1, P1, P2, PE2) provide connections between and share routing information with routers (CE1, CE2) of a customer virtual private network (VPN) as well as routers of other customers' VPNs, which may have overlapping address spaces. A service provider's edge router (PE1)...http://www.google.fr/patents/US6463061?utm_source=gb-gplus-shareBrevet US6463061 - Shared communications network employing virtual-private-network identifiers
