Multi-mode jumpers cannot be plugged in and used, and if the level is not high enough to run 10G, packet loss will occur easily. The core difference between OM1 and OM5 is the effective mode bandwidth, which directly determines how far the same rate can be transmitted and whether it can reach the nominal bandwidth stably.
Relationship between core diameter and wavelength
OM1 and OM2 support the 850nm shortwave window, but the bandwidth is low; OM3 and above are laser optimized and can only exert high-speed capabilities with VCSEL modules. The 50/125 micron structure is the current mainstream multi-mode specification, and the 62.5 micron used in OM1 is rarely used in new projects.
Typical distances for each level
The distance decreases rapidly with the speed. The following is the magnitude reference of common speeds. The actual module specifications shall prevail.
- 10G: OM3 is about 300 meters, OM4 is about 400 meters, and OM5 remains above 400 meters.
- 25G vs. 40G: OM4 can reach about 100 to 150 meters.
- 100G SR4: OM3 about 70 to 100 meters, OM4 about 150 meters.
- OM5 is oriented to short-distance multi-wavelength and reserves bandwidth for future expansion.
New optionalLC-LC 10G multi-mode OM3 two-core jumperTo start, choose OM4 if the density is high or the distance is tight. EB-LINK will give matching suggestions based on speed and length.
Don't use old thread with insufficient grade
If OM1 and OM2 are replaced with 10 Gigabit ports, the link may be barely passable but the margin is insufficient. When the temperature drift is large, bit errors will increase. When relocating or expanding capacity, it is more cost-effective to check the fiber grade first and then decide whether to reuse or replace it, rather than repeatedly checking afterward.
Multi-mode selection depends on the bandwidth budget, and achieving the level in one step can save the cost of subsequent rework and error troubleshooting.