Abstract: To address the problems of complex implementation of cross-domain virtual private networks built in current carrier networks,excessive load on devices at the border of autonomous systems,and the existence of single points of failure,this paper proposes a solution for building cross-domain virtual private networks by virtualization.The scheme consists of four fundamental steps:the establishment of public network tunnels,the establishment of local VPN instances,the virtualization of autonomous system border devices,and the interaction of private network routes of border devices.To evaluate the feasibility and superiority of the scheme,comparative experiments are conducted with the cross-domain virtual private network constructed by the tradi-tional multi-hop EBGP approach in the dimensions of switching capacity,route entries,and label entries.Experimental results show that the cross-domain virtual private network constructed by this scheme enhances the data processing capability of the autonomous system boundary devices and reduces the amount of data to be processed by the autonomous system boundary devices.In general,this improved scheme is advanced and effective for building cross-domain virtual private networks.

Key words: Virtualization, Multi-protocol label switching, Border gateway routing protocol, Autonomous system boundary sevice, Virtual private network