A small form-factor pluggable (SFP) transceiver is a compact, hot-swappable, input/output transceiver used in data communication and telecommunications networks. SFP interfaces between communication devices like switches, routers and fiber optic cables, and performs conversions between optical and electrical signals. SFP transceivers support communications standards including synchronous optical networking (SONET)/synchronous digital hierarchy (SDH), gigabit ethernet and fiber channel. And also they permit the transport of fast Ethernet and gigabit Ethernet LAN packets over time-division-multiplexing-based WANs, along with the transmission of E1/T1 streams over packet-switched networks.
SFP Module is usually called a mini gigabit interface converter (GBIC) because its function is comparable to the GBIC transceiver however with smaller sized dimensions.The SFP transceiver is specified by the SFP Transceiver Multisource Agreement (MSA), that is developed and it is followed by different transceiver manufacturers.
SFP Transceivers have a diverse range of detachable interfaces to multimode/single-mode fiber optics, which allows users to select the appropriate transceiver according to the required optical range for the network.
SFP transceivers are available with copper cable interfaces, which allows a host device designed primarily for optical fiber communications to also communicate over unshielded twisted pair networking cables. Modern optical SFP transceivers support digital diagnostics monitoring (DDM) functions, also known as digital optical monitoring (DOM). This feature gives users the capability to monitor the real-time parameters of SFP, such as optical output power, optical input power, temperature, laser-bias current and transceiver supply voltage.
SFP Transceivers can be purchased with a number of transmitter and receiver types, allowing users to select the appropriate transceiver for each link to provide the required optical reach over the available optical fiber type (e.g. multi-mode fiber or single-mode fiber).
SX - 850 nm, for a maximum of 550 m at 1.25 Gbit/s (Gigabit Ethernet) or 150m at 4.25 Gbit/s (Fibre Channel).
LX - 1310 nm, for distances up to 10 km.
BX - 1490 nm/1310 nm, Single Fiber Bi-Directional Gigabit SFP Transceivers, paired as BS-U and BS-D for Uplink and Downlink respectively, also for distances up to 10 km.
CWDM and DWDM SFP transceivers at various wavelengths achieving various maximum distances: 1550 nm 40 km (XD), 80 km (ZX), 120 km (EX or EZX).
1000BASE-T SFP Transceiver - these modules incorporate significant interface circuitry and can just be used in Gigabit Ethernet, as that is the interface they implement. They are not suitable for (in other words: don't have equivalents for) Fibre channel or SONET.