The Tellabs FlexSym® OLT2 Optical Line Terminal is a multi-purpose Optical Line Terminal (OLT) enabling open, simple, and scalable connectivity for wired and wireless networks over fiber and copper networks. Optical line terminals (OLTs) are used by service providers as the endpoint hardware of a passive optical network (PON) (Flegere/Shutterstock. Their main functions include. SAN JOSE, Calif. Fiber-to-the-home. Ciena's Matt Bolig explains how this shift is setting the stage for co-packaged optics to redefine how bandwidth is delivered inside the data center. It supports multiple technologies, high bandwidth, and a compact size to enable flexible.