Book excerpt: Ensure that your WAN can handle the latest technologies with this must-have strategy guide If a Wide Area Network (WAN) isn't set up properly, it won't be able to meet the needs of the applications being used in the Local Area Network (LAN). And with the emergence of new technologies such as VPNs, multi-service networks, and the mobility of corporate users, the costs involved with running a WAN have changed dramatically. Written by an expert on WAN design, this book provides a comprehensive strategy for choosing the best technologies available for your WAN. It includes analysis of business requirements for WANs, end-user and service provider requirements, and the capabilities and tradeoffs of the available technologies. The book also covers the realities and limitations of QoS, security, multi-service networks, virtual networks, VPNs, multi-homing, roaming, and mobility.