The letter combination ZR in the 10GbE interface stands for Extended Reach. This interface, which uses single- mode fibers and a laser with a wavelength of 1,550 nm, can bridge distances of 80 km. It is used in wide- area networks.
Due to the very high transmission power, significant attenuation is required for shorter connections. To ensure trouble-free use, the ZR optics should be subjected to an optical performance test.
The 10GbE interface 10GBase-ZR is not an IEEE standard, but it is offered by various vendors. It operates at a baud rate of 10.3125 Gbit/s.