[kingu]

I remember when there was some mysterious line cuts near China Lake and Ridgecrest a number of years ago. Large chunks of telco wire were sliced at two points along a major trunk. When 128k modems came out, there was some line issues that were preventing them from being used at full speed. Turned out that right smack between the two line breaks was a house owned by a Russian sleeper who had installed quite a clever little installation to monitor modem communications over telco lines.

I imagine that the only way to tap a fiber line is to make a couple cuts and install whatever device you want somewhere between the breaks.

[driftdiver]

There are other ways if you have the right equipment. A break is way to obvious and would be investigated.

[BwanaNdege]

Fiber optic can have signal injected and removed without cutting. If you make a cut and install your own equipment, that cut/equipment can me pinpointed by a OTDR (Optical Time Domain Reflectometer), basically a laser rangefinder that shows all connections or the first break in the fiber.

The OTDR then gives an optical range to that "event". Plug that data into your Cable Management GIS (Geospatial Information System) software which will then give you a map location for the event.

OptiCon Demo

[GingisK]

I imagine that the only way to tap a fiber line is to make a couple cuts and install whatever device you want somewhere between the breaks.

It just takes a couple of turns of the cable around a photo-multiplier tube. Enough photons leak out of a bend to provide a fully functional tap.