IP learning tunnels - an innovative approach to large scale ethernet VPN services

摘要

There has been a significant amount of research and development effort conducted in the industry on how to provide VPN services using an IP network. This paper describes a new method of implementing VPNs on an Ethernet based switched optical network. The method is called IP learning tunnels (IPLT). The main objectives in the development of IPLT were as follows: centre dot Provide a VPN mechanism that does not require service provider administration in the customer IP address plan centre dot Leverage the significant industry investment and momentum in IP networking centre dot Provide an efficient operations model to support the solution IPLT utilizes IP encapsulation of Ethernet frames to provide layer 2 virtual private networks over a layer 3 IP infrastructure. The technology can also be adapted to provide layer 3 VPN if desired. By using IP as the encapsulation protocol, the technical benefits of an IP network are realized. In addition the economic benefits of leveraging the tremendous investment in IP networks are realized. In any VPN solution, there needs to be a mechanism for identifying a community of interest. Traffic within any one of these VPN communities must strictly remain within. One VPN community must not have connectivity to any other VPN community unless specifically permitted. IPLT utilizes IP multicast technology to define these communities and discover the topology within.