Which multimode fiber types are considered obsolete and no longer recommended?

• A. OM1 and OM2
• B. OM3 and OM4
• C. OM5
• D. All fiber types are recommended

Answer: (A)

Old multimode fiber types limit bandwidth and reach compared with modern laser-optimized fibers. OM1 and OM2 have lower bandwidth-distance performance, which makes them impractical for current and future high-speed networks. For new installations, designers typically choose higher-performance options like OM3 or OM4, and even OM5 for specialized wideband applications. Because of their limited capabilities, OM1 and OM2 are considered obsolete and not recommended for new builds. The other choices reference fibers that are still in use or are newer options, and saying all fiber types are recommended isn’t accurate.