It utilizes single-mode fiber optic cables to carry the optical signals over long distances, providing high bandwidth and low attenuation. In summary, OLT, ONU, ONT, and ODN are integral components of a Passive Optical Network (PON) architecture. That is, if the cores of two optical fibers are close enough, the mode field of light transmitted in. The Passive Optical Network (PON) is the indispensable foundation for delivering ubiquitous, multi-gigabit broadband connectivity, a necessity for modern economies and residential life. What is ODN (Optical Distribution Network)? What is ODN (Optical. In the complex landscape of fiber optic infrastructure, selecting the right cable type—single-mode (OS1/OS2) or multimode (OM1/OM2/OM3/OM4/OM5)—can define a network's speed, reach, and cost-effectiveness.