Virtual private networks and their role in e-business

The idea of using a low-cost public network such as the Internet to build a private network is intriguing. In this article, we will focus on virtual private networks (VPNs), which leverage the Internet to provide cost-effective, secure communications. We will discuss the challenges of implementing VPNs based on the Internet Engineering Task Force (IETF) Internet protocol security (IPSec) standards. We will cover various aspects including encryption, authentication, Internet key exchange (IKE), and public key infrastructure (PKI) as they relate to IPSec-based VPNs. We will discuss the major issues facing enterprises, service providers, and end-users in implementing intranets, extranets, and remote access VPNs. We will elaborate by discussing how the Lucent VPN firewall handles the various issues and scenarios described here, and how customers in implementing robust VPNs, use it in practice. We also will touch on other VPN solutions and product architectures, and briefly mention other Lucent VPN products. In closing, we will discuss future VPN challenges, including the impact of Internet protocol version 6 (IPv6).3