Short answer: Usually yes, you use them in pairs, but the “pair” can be a media converter on one end and a fiber switch (or SFP in a switch) on the other, as long as both sides speak the same speed, wavelength, and optical mode. BiDi optical modules must be used in pairs to achieve bidirectional data transmission. For example, if paired BiDi modules are connected to Device A (uplink) and Device B (downlink), the duplexer of Module A must have a receive wavelength of 1550 nm and a transmit wavelength of 1310 nm, while the. In fiber optic communication systems, optical transceivers play a critical role in ensuring seamless data transmission. Among these devices, single-fiber modules (BiDi) and dual-fiber modules (standard duplex) are two primary categories. Arista transceivers and cables are all hot-swappable pluggable devices, compliant with industry standards, and certified on all Arista platforms unless otherwise stated. This document. Do converters need to be used in pairs? Can you mix brands? What wavelengths matter? This guide answers it all with clear diagrams, step-by-step checklists, and field-tested troubleshooting tips., one end TX1310/RX1550, the other end TX1550/RX1310).