13.4 Dedicated Extranet VPN

Dedicated extranet VPNs use VPNs to allow any-to-any communications between different companies. This type of VPN allows sharing of external data between separate companies and enables companies to exchange data with each other over the Internet with a specific level of security. The extranet topology can be implemented with either the overlay model or the peer-to-peer model. A dedicated extranet topology could be used to construct a network of VPNs that would allow any-to-any communications for a company and its partners . This type of implementation can assist in increasing productivity for an organization by allowing the many businesses to exchange information freely to enhance productivity for each organization. The organizations involved would usually be in the same industry, for example the airlines and the travel agents . One might ask, why not just use the Internet to provide this any-to-any communication? That is not a bad idea, but what about the quality of the communication? This extranet implementation is used to provide the QoS levels required for dependable data transfer. Figure 13-6 shows an example of a full-mesh dedicated extranet application. The airline network and travel agent network are both made up of two sites. Through this configuration, VPNs will be created that will allow any one of the CE sites to communicate with any other CE site.

Figure 13-6. Dedicated Extranet Application