Virtual private networks (VPNs) connect branch offices and remote user over a shared or public network such as the Internet, with the same security and availability as a private network. Because VPNs use an existing shared wide area network (WAN) infrastructure, costs are lower and deployment is faster than traditional private networks. Telecommuters, mobile users and branch offices all require dependable access to company intranets, and businesses of all sizes are now deploying VPNs.