nt optical switches, reconfigurable optical add/drop multi- plexers (ROADMs) that include the functionality of SDH/SONET restoration, DWDM and Coarse Wavelength Division Multiplexing (CWDM) systems, optical cross-connects, and new maintenance and management tools for optical networks. In an intelligent optical network, these devices can communicate with each other to discover the topology, enabling simple A-through-Z provisioning. The strategic direction is to migrate to mesh topology where and when appropriate, choosing expenses that reflect revenue margins. For example, carriers should continue to dedicate a source of restoration for those services that expect it, such as private line Chapter 11 Optical Networking or voice, but rely on shared mesh protection or even unprotection for resilient pro- tocol services such as IP, Frame Relay, or ATM. The new-generation service provider's solution is to offer new, high-bandwidth services, optical VPNs, and public services that act like private networks. Optical networks are the only architecture that can allow IP to scale to meet the demands of the new generation, and this implies the marriage of IP and optical networks, which is discussed later in this chapter. Bandwidth Abundance As mentioned earlier in this chapter, service providers may choose to pursue the strategy of migrating to intelligent optical networks to guarantee growing reve- nues. Optical technology is revolutionizing networking and introducing a new era of abundant capacity, stimulating developments and growth of bandwidth-hungry applications. These bandwidth-intensive applications, however, are much more cost-effective when the network provides just-in-time bandwidth management options as well. And, of course, these advanced applications demand more than bandwidth; they look for service qualities that allow control of parameters such as delay, jitter, loss ratio, and throughput. Next-generation SDH/SONET quadruples the bandwidth per channel about every two years. In addition, DWDM improvements are re