Cisco MGBSX1 Gigabit SX Mini-GBIC SFP Transceiver
GBIC / SFP modules
GBIC and SFP are both an optical transceiver used to convert between the optical signal and the electrical signal. GBIC stands for Gigabit Interface Converter. SFP is short for Small Form Factor Pluggable. Normally, SFP is considered an upgraded version of the GBIC module. But GBIC and SFP are the same in performance. The only big difference between them is their size. The SFP module is much smaller than the GBIC module. For this reason, SFP is in most cases also called mini GBIC.