A Small Form-Factor Pluggable (SFP) is a compact, hot swappable, input/output device that is used to for both telecommunication and data communications applications. SFP is responsible for converting between the electrical and optical signals, while allowing both receive and transmit operations to take place. SFP transceivers can be leveraged in a variety of high-speed Ethernet and Fibre Channel deployments. SFP is also sometimes referred to as mini Gigabit Interface Converter (GBIC) because its small form factor and both provide similar functionality.
This article mainly introduces three basic types of 1000BASE SFP transceivers: 1000BASE-T SFP, 1000BASE-SX SFP, and 1000BASE-LX/LH SFP.
This SFP transceiver for copper networks operates on standard Category 5 unshielded twisted-pair copper cabling for links of up to 100 meters (~330 feet) in length. These modules support 10 Megabit, 100 Megabit, and 1000 Megabit (1 Gigabit) auto-negotiation and auto-MDI/MDIX. MDI is Medium Dependent Interface. MDI-X is Medium Dependent Interface Crossover.
This SFP transceiver is used only for multimode fiber networks. It is compatible with the IEEE 802.3z 1000BASE-SX standard, and it operates over either 50 microns multimode fiber links for a distance of up to 550 meters (~1800 feet) or over 62.5 microns Fiber Distributed Data Interface (FDDI)-grade multimode fiber for a distance up to 220 meters (~720 feet). It can also support distances of up to 1 kilometer (~0.62 miles) over laser-optimized 50 microns multimode fiber cables.
This SFP transceiver operates over standard single-mode fiber-optic link spanning distances of up to 10 kilometers (~6.2 miles) and up to 550 meters (~1800 feet) over any multimode fiber. It is compatible with the IEEE 802.3z 1000BASE-LX standard. 1000BASE-LX/LH SFP transceivers transmitting in the 1300 manometers wavelength over multimode FDDI-grade OM1/OM2 fiber require mode conditioning patch cables.
In different situations, you may need to choose the different SFP. If a network engineer needs to use an existing switch in a new role in a campus network, the engineer could simply buy a new 1000BASE-LX SFP to replace the old 1000BASE-T SFP and reduce the extra cost of buying a new switch. For example, when using a switch so that it connects only to other switches in the same building, the switch could use 1000BASE-T SFP and copper cabling. Later, if the company moved to another location, the switch could be repurposed by using a different GBIC that supported fiber-optic cabling, and different connectors, using 1000BASE-LX to support a longer cabling distance.
In order to make your network achieve peak performance, choosing different SFP is necessary. The transmission distance and compatibility need to be considered. fiber-mart, a leading and professional fiber optic SFP transceiver module provider, has a large inventory of 1000BASE-SX SFP, 1000BASE-T SFP and 1000BASE-LX/LH SFP. It is always your primary option.