What is a Transceiver

Optical fiber connections are constructed with a combination of a transceiver (sometimes called a GBIC – for GigaBit Interface Converter). The transceiver accepts digital signals from the Ethernet device (switch or adapter card) and converts them to optical signals for transmission over the fiber. The transceiver has electronic components to condition and encode/decode data into light pulses and then send them to the other end as electrical signals. Although a number of different form factors for this GBIC have
been defined by standards bodies, the most common is the SFP (Small Form Factor Pluggable Transceiver). The term GBIC initially was used for a specific form factor, but with the widespread adoption of the smaller SFP standard form factor, the term GBIC has fallen into the vernacular as a general term for an optical transceiver. (Some people even call the SFP a “mini-GBIC”, but that designation does not come from any standards body.)