The present invention provides a method and an apparatus for establishing a virtual private network that operates over a public data network. One embodiment of the present invention includes a system that selects a plurality of entities coupled to the public data network to include in the virtual private...http://www.google.com.hk/patents/US6226751?utm_source=gb-gplus-share專利 US6226751 - Method and apparatus for configuring a virtual private network
