Three tremors on the IT landscape (Web Services, Networked Remote Storage and Grid Computing) are triggering an exponential growth in inter-site traffic. Organizations will need to react proactively by moving from multiple dedicated single-application networks to a more flexible, adaptable network architecture—an Adaptive WAN. This paper looks at how Web Services, Networked Remote Storage and Grid Computing are driving the need for Adaptive WANs. The paper explains how Ciena's Adaptive WAN approach provides enterprises a simpler lower cost means to reliably extend their current and developing mission critical applications between sites, over both copper and optical lines. Various scenarios are examined.