Unlike underground fiber cables, direct buried cables are installed without protective conduits. Indoor cables can be installed in raceways, cable trays above ceilings or under. Premises cables can be installed in cable trays, conduit, innerduct or special types of cable hooks. Fiber optic cables should. Minimize mechanical pressure on the outer sheath at crossing points: (armoured) cables crossing each other generate points of high pressure, so it is important when laying in figure 8 loops it is done in a correct way. These cables are specially designed with robust armor to withstand the harsh underground environment, protecting against rodents, rocks, and soil shifts.