The host bus adapter (HBA)
The server connects to the SAN through a host bus adapter (HBA) — an I/O adapter card that fits inside your server and connects it to the fabric layer.
The Gigabit Interface Connector (GBIC)
The Gigabit Interface Converter (GBIC) is where the cable plugs into the HBA card. Every HBA has a GBIC that snaps into an opening in the card or is soldered to the card. The openings in the GBIC extend out the back of the server so you can plug in the cable. The GBIC houses the laser and electronics that convert the data inside your server into light pulses that travel over the cables. GBICs are used not only in the HBA, but in every device in the SAN. Anywhere an optical cable has to be plugged in, you find a GBIC.
