Calculators

OM1, OM2, OM3 and OM4 Fiber

In ANSI/TIA-568-C.3, the TIA adopted the nomenclature for fiber found in the international standard ISO/IEC 11801. The multimode fiber is prefixed with “OM.”

The new designation in ANSI/TIA-568-C should alleviate some of the confusion associated with application support distance issues. Each “OM” has a minimum Modal Bandwidth (MBW) requirement.

	1000BASE-SX	10GBASE-S	40GBASE-SR4	100GBASE-SR 10
OM1	275 m	33 m	Not specified	Not specified
OM2	550 m	82 m	Not specified	Not specified
OM3	Not specified	300 m	100 m	100 m
OM4	Not specified	500 m*	150 m	150 m

*The IEEE has yet to officially give a distance for 10GBASE-S on OM4 fiber. The distances are decided by the IEEE in 802.3, not The TIA or ISO/IEC cabling standards. Some glass vendors say 500 m, but most are now quoting “up to 550m.”