In private local area networks (LANs), IP-based intranets have fundamentally changed the way
companies conduct their business. Companies are moving their business applications to their
intranets to extend over a wide area network (WAN). Companies are also embracing the needs
of their customers, suppliers, and partners by using extranets (an intranet that encompasses
multiple businesses). With extranets, companies reduce business process costs by facilitating
supply-chain automation, electronic data interchange (EDI), and other forms of network
commerce. Also Businesses of all types and sizes are facing the challenge of integrating data,
voice and video traffic in easily managed, scalable, economical and flexible networks. Virtual
Private Networks (VPNs) have emerged as a fundamental solution for meeting these challenges
and business customers are now looking to service providers for value-added, cost-effective
VPN services.