Using WRAP, an ISP can provide a Virtual Private Network (VPN) service by creating for each enterprise a secure (virtual) transit realm that connects to each of its enterprise sites. The enterprise directory and routing system only needs to deal with the topology of the enterprise network with this ``virtual'' realm directly interconnecting all the sites. The different sites of the VPN can even have overlapping IPv4 address assignments (typically 10.X.X.X) yet still communicate directly without renumbering.
The ISP implements this virtual realm simply by providing routing and secure communication between each site. In this case, the overhead from WRAP is 12 bytes. As an optimization, the ISP can provide at each site a relay agent address for each other remote site in the VPN so packets can be addressed as though each site was directly connected through a relay to each other site, reducing the header overhead to 8 bytes. Thus, WRAP can also obviate the need to deploy MPLS [12].