Fiber optic data communication networks face unique requirements for applications such as disaster recovery of multiterabyte and petabyte databases. We present experimental results from several enterprise computing testbeds that evaluate dense wavelength-division multiplexing (DWDM) performance in metropolitan area datacom networks. Many networking issues can be addressed through the components used within the DWDM platform; we discuss how current and emerging requirements can be addressed by new packages for 10-Gbit/s links, clock recovery circuits, and wavelength lockers. A comparison of three DWDM platforms evaluated in these testbeds is given, including features such as network bandwidth, scalability, performance over distance, and ease of management. We also report performance of datacom protocols such as enterprise system connection (ESCON), fiber connection (FICON), and FICON Bridge, when extended beyond industry standard distances using DWDM.