SFP or mini-GBIC is a small transceiver that plugs into the SFP port of a network switch and connects to Fiber Channel and Gigabit Ethernet (GbE) optical fiber cables at the other end. SFP modules mainly act as an interface between a networking device like any switch, router, Repeater, Multiplexer, etc. and its interconnecting cable. By choosing the appropriate SFP module, the same electrical port on the switch can connect to fibers of different types (multimode or single mode) and different wavelengths. If the fiber is upgraded, the SFP module is replaced. The SFP converts the serial electrical signals to serial optical signals and vice versa. SFP modules are hot swappable and contain ID and system information for the switch.

The SFP transceiver has an immense variety available, each with different transmitter or receivers. This allows the user to configure and customize the transceiver to get the proper optical reach with either a multimode fiber or single-mode fiber type. Moreover, the optical SFP module comes in four categories - SX, which is 850nm, LX, which is 1310nm, ZX, which 1550nm and DWDM. Such as Gigabit Ethernet SFP modules include 1000BASE-T, 1000BASE-SX, 1000BASE-LX/LH, 1000BASE-EX, 1000BASE-ZX, or 1000BASE-BX10-D/U.

Certain SFP transceivers always use fiber optic cables as interface, also use copper cables as interface. This causes a device in the network to send their data over shielded or unshielded twisted pair cable. Usually such copper cable interfaces are used when the information to be transmitted needs to cover only shorter distances where use of copper cable is more economical than optic fiber cables.

XFP, SFP+ for 10 Gigabits
The 10G module has been developed from 300Pin, XENPAK, X2, XFP and finally achieve with the same size as SFP which can transmit 10G signals called SFP+, as SFP supported only up to 4.25 Gbps. In comparison to earlier XENPAK or XFP modules, SFP+ modules leave more circuitry to be implemented on the host board instead of inside the module. SFP+ transceiver had replaced XFP module and became the mainstream in the market. SFP+ transceiver is interchangeable with SFP transceiver and can be used in the same cases as SFP transceiver. SFP and SFP+ have the same size and appearance, but in a different standard.

SFP - Gigabit up to 80km
XFP - 10G for up to 80km
SFP+ - 10G for up to 100km

For 10G applications, SFP+ transceiver has a smaller footprint and lower power consumption than XFP transceiver. There are 10G SFP+ module, BiDi SFP+ module, CWDM SFP+ module, DWDM SFP+ module available at FiberStore.