1000BASE-SX VS 1000BASE-LX SFP Transceivers

What is 1000BASE-SX SFP?

1000BASE-SX is a gigabit Ethernet standard over fiber optic. It is used for operating on wavelengths of 850 or 1310 nanometers. In other words, 1000BASE-SX can operate over both single-mode fiber and multimode fiber. It has a working distance of up to 2km over single-mode fiber and a maximum length of 550 meters on multimode fiber. This standard is widely used in large office buildings, co-location facilities, and carrier-neutral Internet exchanges. The “SX” stands for short distances between 220m and 550m reach over multimode fiber. Taking FS 850nm 1000BASE-SX SFP module (SFP1G-SX-85) as an example, transmission reaches 275 meters by 62.5μm/125µm OM1 fibers, and up to 550 meters if 50μm/125µm OM2/OM3/OM4 fibers are deployed.

What is 1000BASE-LX SFP?

IEEE 802.3 Clause 38 specifies 1000BASE-LX as a standard for implementing Gigabit Ethernet networks. The “LX” in 1000BASE-LX stands for long wavelength, indicating that this version of Gigabit Ethernet is intended for use with long-wavelength transmissions (1270–1355nm) over long cable runs of fiber optic cabling. 1000BASE-LX LC SFP transceiver is mainly intended for connecting high-speed hubs, Ethernet switches, and routers in different wiring closets or buildings using long cable runs. Due to the low cost and extended reach that meets most enterprise networks, 1000BASE-LX has become one of the most popular standards. Such as SFP1G-LX-31, is an LX single-mode transceiver that operates over a wavelength of 1310nm for up to 20km.

1000BASE-SX VS 1000BASE-LX SFP Transceivers

The 1000BASE-SX and 1000BASE-LX LC SFP transceivers are used for Gigabit Ethernet over fiber optic cabling, following the IEEE 802.3z standard. There are nuances shown in fiber types, transmission distance, dispersion, and scenarios.

Types of Optical Fibers

Regarding the types of optical fibers, the 1000BASE-SX LC SFP transceiver continues to work with single-mode or multimode fiber, the latter has a thicker core and allows for higher speeds but at shorter distances. On the other hand, the 1000BASE-LX LC SFP transceiver works with single-mode fiber for both data transmission and reception.

Transmission Distance

In terms of transmission distance, the 1000BASE-SX LC SFP transceivers are suitable for short distances, typically within small areas or buildings, reaching up to 2km. In contrast, the 1000BASE-LX LC SFP transceivers are primarily used for long-distance transmission, supporting distances of up to 20km.

Dispersion

Dispersion characteristics differ between the two types of optics. The 1000BASE-SX SFP modules are affected by modal dispersion, as light rays follow different paths through the fiber, resulting in varied arrival times at the receiving end. This mode of dispersion limits the distance achievable. In contrast, the 1000BASE-LX SFP modules are affected by waveguide dispersion, caused by the light's width being larger than the core of the fiber. While this allows for better control of photon paths, it is more susceptible to microbeads, twists, and stress on the fiber.

Application Environment

The application environment for the 1000BASE-SX SFP module is commonly found in short-range applications within local area networks (LANs), data centers, and campus networks. On the other hand, the 1000BASE-LX SFP module is suitable for long-range applications, including wide area networks (WANs), metropolitan area networks (MANs), and long-haul connections between different locations.

Conclusion

1000BASE SFP transceivers are widely used components for Gigabit Ethernet applications. FS offers a wide range of 1000BASE SFP transceivers compatible with various brands like Cisco, Juniper, Dell, Finisar, Brocade, and Netgear. If you have any specific product requirements, please feel free to send us your request.