The WS-G5487, 1000BaseZX operates on ordinary single mode fiber optic link spans of up to 70 km in length. Link spans of up to 100 km are possible using premium single mode fiber or dispersion shifted single mode fiber (premium single mode fiber has a lower attenuation per unit length than ordinary single mode fiber; dispersion shifted single mode fiber has both lower attenuation per unit length, and less dispersion).

The WS-G5487 must be coupled to single mode fiber optic cable, which is the type of cable typically used in long haul telecommunications applications. The WS-G5487 will not operate correctly when coupled to multi-mode fiber, and it is not intended to be used in application environments (e.g. building backbones, horizontal cabling) where multi-mode fiber is frequently used.The WS-G5487 is intended to be used as a Physical Medium Dependent (PMD) component for Gigabit Ethernet interfaces, as found on various switch and router products.