That step alone has the potential to tremendously simplify the design of wide-area networks by minimizing the difficulties of installing, configuring, and managing the remote links. Many organizations have concerns about transporting sensitive information across a shared IP network because that traffic could be intercepted or even modified by hackers or Internet thieves. Thus, in many cases a VPN carries encrypted traffic. Most people associate VPNs with tunnels through the Internet that carry encrypted traffic. See a glossary of VPN terms.
Savings are especially dramatic for International locations.
In situations where it makes sense to piggyback voice traffic, the savings are further amplified. Moreover, they permit a single WAN interface to serve multiple purposes, from branch internetworking, to extranet termination for partners, to local provisioning of high-bandwidth lines to dial access providers. As a result, fewer WAN interfaces are required, and exposure to equipment obsolescence is reduced. In addition, because VPNs are independent of origination protocols, they enable remote access users to continue using business-critical legacy equipment, protecting the investment in existing hardware and software systems. But that's only the beginning of lowered support costs.