 protocols, which used hardware (routers, switches, and other adjuncts) to control traffic in packet networks. WA SDNs are a layer of software that runs on top of dedicated wavelengths and Gigabit Ethernet. Multiprotocol Label Service (MPLS), which does prioritize voice and video, is still used by enterprises. However, the routing is rigid and the capacity is limited. It's not uncommon for MPLS and WA SDN to be present in the same enterprise networks with MPLS under the control of WA SDN. Telephone companies, particularly in urban and suburban areas, are often dropping support for older, slower, inflexible services wherever fiber-optic cabling is available. The older services, mainly T1, T3, and DSL have severely limited capacity and less-flexible configurations than newer broadband. Moreover, it is more costly for telephone companies to support them www.TechnicalPDF.com than the more flexible Carrier Gigabit Ethernet and Dedicated Wavelength services. For these reasons, and because customers are demanding higher capacities, telephone companies are phasing out T1, T3, and DSL wherever fiber cabling is available. As it's difficult for organizations to accomplish their day-to-day functions when their broadband networks are unavailable, reliability and availability are critical concerns. Many customers take it for granted that because there are few network outages, their broadband networks will be available 7 days a week, 24 hours a day. However, for large financial services companies and medical institutions, this is not adequate. Most of these large institutions have duplicate, backup fiber-optic lines connecting their buildings to broadband links if their primary links fail. Fiber-optic lines cut by a backhoe or a failure in the telephone company's equipment can cause failures. Managed services are one way that carriers differentiate themselves from regional and smaller competitors, who sell discounted broadband services. Examples of managed services are managing Wi-Fi networks and consulting on data centers. In 