Just realized fiber optic cables can degrade from too much bending even if they look fine on the outside

I read a white paper from Corning last month that said a tight 90 degree bend can cause micro-cracks in the glass that kill signal strength over time, and now I'm double-checking every corner I ran in a new apartment complex downtown last week.

3 comments

3 Comments

oliverhernandez24d ago

Just run your hand along any tight bends you can reach and feel for a flat spot or hear a little crunch. If the cable feels flattened at all, that's a problem. Another trick is to grab a cheap vfl and shine it at the bend, if you see light bleeding through the jacket, you've got micro-fractures for sure. I've had to re-terminate a few runs where the installer stomped on the cable and it looked perfect on the outside but signal was totally tanked.

jennifer83324d ago

Pulled out my old OTDR from the networking closet and tested a run that had been acting flaky for months. Found the exact spot where a cable was pinched behind a desk - looked fine but the trace showed the loss plain as day. Saved me from redoing the whole pull.

the_anthony23d ago

@oliverhernandez that visual fault locator trick is gold, but I've also had luck swapping a cable with a known good one from the floor patch panels to rule out the horizontal run entirely.