OS2
Single-mode fiber grade whose reach is limited by attenuation and dispersion rather than modal effects, making it the generation-agnostic plant choice that rides lane-rate upgrades as a transceiver-only swap.
Current numbers
16 fibersper 800G-DR8 / 1.6T link via MPO-16; OS2 single-mode trunked once rides 800G → 1.6T → 3.2T on transceiver swaps alone