zed to support voice. Before the current era of bandwidth abun- Next-Generation Networks and Convergence dance, controlling latency was an easier task than providing bandwidth. Bandwidth was considered to be at a premium, requiring high utilization and oversubscription by customers. Because QoS was a prerequisite to supporting voice, controlling latency was the dominant traffic-engineering issue. In the traditional world, all car- riers and some enterprises desired measured use for network chargeback, so accountability was a critical concern. In terms of network ownership, traditional thinking was that carriers should own the facilities to maintain control. Finally, the basic business model was one where transport was considered to be the business. In the traditional enterprise, the main goal of an enterprise network was seen to be the linking of enterprise sites. The network staff was generally divorced from the Web site developers. The main objective of network management was to man- age the network as a cost center, with the major focus being on controlling the size of the "phone bill." In terms of network architecture, the traditional enterprise saw the use of separate voice and data networks, with most traffic being local to a nearby server. The key consideration was to provide high availability, first and fore- most for voice, with data being a secondary consideration. Network optimization activities were supported by predictable traffic, predictable service providers, and predictable rates and tariffs. The preference in terms of network infrastructure was to build private networks; they were the norm and favored over public networks, whose use was the exception. Current Operating Thinking The assumptions at play with the new enterprise are vastly different from the tradi- tional thinking. Today, using the public Internet for communications is considered as important as using enterprise networks. More often than not, the networking staff works with the Web site and e-commerce operations. The new network man