functionality could be replaced by part of a single converged network. ATM was being positioned by some vendors to implement such a replacement. During the 1990s, service providers exploited ATM by using converged WAN services, and although the technology did not achieve the critical mass necessary to be a competitor of lower-level SDH/SONET services, it was leveraged effectively both for revenue generation and for early convergence and migration of legacy services. As such providers rolled out ATM as a high-speed overlay network, it was successfully adopted by many corporations for their wide-area data networks. For example, in the United Kingdom service providers-including BT-have used the ATM network infrastructure to backhaul customer Internet traffic from the Digital Subscriber Line (DSL) local loop via the DSL Access Multiplexer (DSLAM) to the core IP access servers. It would appear that ATM is firmly established; however, vendors of DSLAM technology are now aiming at the IP DSLAM market. Industry analysts are expecting a global migration of services to IP/MPLS and that the associated converged IP technologies will replace ATM. For example, in 2000 Switzerland's incumbent telecom operator purchased an IP/MPLS router network from Cisco Systems (Rastislav, 2001). This was one of the first major signs of a shift away from ATM solutions, although the network purchase included a large ATM Overlay Network Concepts feeder network. The general goal of this project was to converge the Swiss network around an IP and MPLS routing platform. Voice/IP gateways were deployed. Consisting of 35 points of presence located throughout Switzerland, the national Swiss platform that was created ran directly over dark fiber and, unlike many other operators, even bypassed the SDH network. This IP/MPLS network set the global trend during 2000. The use of dark fiber and the bypassing of the SDH network were pivotal in changing perceptions of MPLS capabilities within the industry. It would be a fair comment that globally there has bee