the move toward full-speed, end-to-end 1 and 10 GbE in the WAN to support native Ethernet and IP over optics communication networks that next-generation carriers will set out to deploy in the next couple of years. This raises a pertinent question: Does the need and/or desire to deliver an Ethernet handoff to the customer require an Ethernet at the core metro infrastructure, or can such handoffs be supported more cost-effectively and reliably using a next-generation SONET platform that has Ethernet only at the edge? Up to 70 percent of corporate WAN traffic is LAN data and less than 10 percent of WAN traffic is voice. Yet up to 70 percent of WAN links use DS1 and DS3 private-line, voice-oriented circuits to link up to other metro cor- porate sites or to link into the backbone. 15 Hence, the challenge for carriers is how to migrate from their current TDM/ATM-based networks to a world dominated by packet traffic driven by the growth of the Internet (which according to the best data is still growing at 80 percent a year although there may be some slowdowns in the future). 16 As part of an assessment of the kind of architectures that carriers should deploy for supporting evolving networks, it is interesting to note some research at the time of this writing. Communications Industry Researchers, Chapter 1 Figure 1-4 Broadband/TLS applications. Main Office Metro Access SN/CO/POP Backup Office Metro SN/CO/POP Metro Core Access Broadband and/or Storage Site Broadband (or OC-12/48/192) Internet Remote Office Remote Office Inc. (CIR), an industry analysis firm, released a report17 on the optical- networking strategies of two U.S. Incumbent Local Exchange Carriers (ILECs). Included in the report is an analysis of the wholesale wavelength services market. CIR said that it "thought the wholesale lambda services market would remain limited to the CLEC space for the foreseeable future. Some of the CLECs, such as metro carrier's carriers like Sigma and Telseon, are seeing more interest in wholesale lambda services at OC-48 rates a