Carry 100 GbE Ethernet across up to 20 km of single-mode fiber while using one simplex LC fiber path. The ACCORTEC QSFP-100G-LR20BD-D-ACC is a 100GBASE-BXD bidirectional optical transceiver in the QSFP28 form factor, built for Arista-compatible network interfaces. Its simplex optical connection reduces the fiber count required for a point-to-point 100 GbE link compared with a conventional duplex-fiber connection. Bidirectional optics place transmit and receive traffic on the same single-mode strand through separate optical directions. The far end of the link requires a compatible complementary 100GBASE-BXD optic so both endpoints can communicate over the shared fiber. This makes the module relevant where an existing fiber route has limited available strands, including building-to-building connections, campus backbone segments, and data-center extension links. Use the module in a QSFP28 port that accepts Arista-compatible 100 GbE optics and plan the optical path around its 20 km maximum distance. The simplex LC interface calls for a single-mode simplex patching arrangement from the equipment port through the structured cabling path. Its distinguishing characteristic is bidirectional 100 GbE transport over one fiber strand, combining long-reach optical distance with reduced fiber consumption.