TIA-598-C fiber color code — positions 1–12
1Blue
2Orange
3Green
4Brown
5Slate
6White
7Red
8Black
9Yellow
10Violet
11Rose
12Aqua
Fibers 13–24 repeat the same twelve colors with a black tracer stripe (black gets a yellow tracer). Buffer tubes follow the same sequence.
Splice & connector loss
| Fusion splice | typ 0.02–0.10 dB |
| Mechanical splice | typ 0.10–0.50 dB |
| Connector, mated | typ 0.20–0.75 dB |
Loss budget = (km × dB/km) + splices + connectors + margin
dB quick math
| 3 dB | = 1/2 power |
| 10 dB | = 1/10 power |
| 20 dB | = 1/100 power |
| dBm vs dB | dBm is absolute; dB is relative |
| 0 dBm | = 1 mW reference |
Minimum bend radius
| Under load | 10 × cable OD |
| No load | 8 × cable OD |
| G.657 | bend-insensitive; eases tight drops |
Tighter bends → macrobend loss. Never kink; respect the radius.
Fiber types & reach
| OS2 SMF | long-haul / OSP · 1310 / 1550 nm |
| OM3 MMF | 100 m @ 10G (aqua) |
| OM4 MMF | 150 m @ 10G (aqua/violet) |
| OM5 MMF | SWDM wideband (lime) |
| Rule | SMF for distance, MMF for short runs |
Connectors & polish
| LC | small-form, duplex — the data-center default |
| SC | push-pull — legacy plant / PON |
| MPO | 8/12/24-fiber ribbon — 40/100G trunks |
| UPC (blue) | return loss ~50 dB |
| APC (green) | 8° polish, ~60 dB — PON / RF video |