A cable consisting of multiple fiber-optic cables bundled together and enclosed in a protective sheath. Direct burial fiber-optic cabling is designed to be buried in trenches and contains a gel filling that protects the individual fibers from temperature and moisture variations.
A strip of strengthening material runs axially down the cable to prevent excessive bending, which can fracture the individual fibers.
Direct burial cabling can have steel-armor construction with heavy waterproof polyethylene jackets and can contain either multimode or single-mode fiber-optic strands.
Graphic D-23. Direct burial fiber-optic cabling.
Direct burial cabling is more cost-effective than single-fiber cabling for long outdoor cable runs between buildings or across a campus because it allows for future bandwidth upgrades.