ABSTRACT
A Virtual Private Network (VPN) is a concept used to build a secure and private communication path on top of a public communication network such as the Internet. In other words, VPN is an overlay network that uses the public network to carry data traffic between corporate sites and users, maintaining privacy through the use of tunneling protocols and security procedures. VPNs were designed to support secure remote access for static connections and are based on the assumption that connection information (e.g., IP address) would not change. Mobile users, however, access information through wireless networks, and their underlying access networks may change over time. Due to their dependency on static, persistent connection information, traditional VPNs are not suitable for mobile users who wish to access secure information through wireless networks. Furthermore, using wireless networks to carry sensitive data introduces several security issues. Mobile VPN technology attempts to extend the VPN concept to support secure data access over public, unsecured wireless networks. This chapter presents several challenges related to Mobile IPsec (Internet Protocol Security) VPNs architectures and discusses some widely used solutions and implementations.
