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.

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.”


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