In duplex fiber applications, the Tx (B) should always connect to the Rx (A), regardless of how many patch panel adapters or cable segments are in the channel. Duplex polarity becomes significantly more complex when using multi-fiber MPO-type trunk cables. When it comes to the connection between two fiber optic transceivers, the following four factors should be considered: wavelength, speed, fiber type, and connection to the switch. In a fiber link, the data is transmitted from one end to another, and fiber transceivers are. Single fiber modules (BiDi) use one fiber for both transmitting and receiving data. Dual fiber modules use two fibers. They are easier to set up and give steady communication.