1000BASE-ZX is a non-standard but multi-vendor term to refer to Gigabit Ethernet transmission using 1,550 nm wavelength to achieve distances of at least 70 kilometres (43 miles) over single-mode fiber. Some vendors specify distances up to 120 kilometres (75 miles) over single-mode fiber, sometimes called 1000BASE-EZX. Ranges beyond 80 km are highly dependent upon the path loss of the fiber in use, specifically the attenuation figure in dB per km, the number and quality of connectors/patch panels and splices located between transceivers.
