 not been stolen. Once the customer is authenticated, another policy manager that stores account and customer profile information might take over. This policy manager is responsible for making sure customized Web portals are delivered the way the customer has previously requested. It also provides the customer with access to subscription-based services and account information. A more complex policy management example involves virtual private network (VPN) services. VPN services have become a viable, less costly alternative to leased-line services. VPN devices communicate at either end of an Internet connection, such as between two corporate locations, to create secure, dedicated tunnels for sensitive traffic. VPNs are also used to provide Chapter 2 - A Detailed Look at OSS remote users with secure access to corporate network services and intranets. Tunnels are only sustained for the duration of the specific session for which they have been requested. A VPN architecture is comprised of servers that create and manage the tunnels across the Internet, and one or more policy managers that manage the servers, handle tunnel provisioning requests, and manage access, security levels, quality of service parameters and traffic priority. Picture a corporate user placing a request through an intranet for a high security, point-to-point videoconference between his desktop in Houston and a conference room in London. The policy server first checks to see if the user has access rights for videoconferencing. In this case he does because he is an executive vice president. The policy server then checks to make sure capacity is available on the serving devices for the time requested and, perhaps, gives this request priority over other requests sent to the servers at either end. When the time comes for the videoconference, the policy server sends commands to the end point devices in Houston and London to provision a tunnel between them, with instructions to route traffic to the appropriate IP addresses in each office. It sets the secu