DWDM · Dense Wavelength Division Multiplexing
Multiplexing many wavelengths onto one fiber pair; it is what turns leased or owned dark fiber into the aggregate inter-site bandwidth a multi-campus training run needs.
Current numbers
80–120 kmsingle-span amplified DWDM reach of the 800ZR coherent interface (OIF IA, Oct 2024); ZR+ extends past 1,000 km