How Many Types of SFP Transceivers Do You Know

Posted on by FS.COM

Gigabit Ethernet has supplanted its predecessor—Fast Ethernet in wired local networks and becomes ubiquitous throughout the world, serving as one of the most prevalent enterprise communication standards. The Gigabit Ethernet standard supports a theoretical maximum data rate of 1 gigabit per second (Gbps)(1000 Mbps), that is 10 times faster than Fast Ethernet, yet is compatible with existing Ethernet. To link your switches and routers to a Gigabit Ethernet network, you need a Gigabit Ethernet transceiver as a transmission medium. This article intends to introduce the most commonly used one—SFP transceivers.

Basics of SFP Transceivers

SFP (small form-factor pluggable) transceiver is the industry standard option for Gigabit Ethernet applications on switches, routers, or modular SFP blade slot. Basically, it is a hot-swappable and compact input/output (I/O) device which provides instant fiber or copper connectivity for Fiber Channel, Gigabit Ethernet, synchronous optical network (SONET), and other communication standards. SFP transceiver module also makes network upgrade easier due to its compatibility, hence it can be adapted to your existing infrastructures.

Common Types of SFP Transceivers

SFP transceivers are available with various transmitter and receiver types, which facilitates users to select the appropriate transceiver module for different optical reach and optical fiber type (single-mode fiber or multimode fiber) required by every different link. SFP transceiver modules can be broken into several different categories:

1000BASE-T SFP Transceivers for Copper Networks

1000BASE-T SFP Transceiver operates on standard Cat5 UTP (unshielded twisted-pair) copper cabling of link lengths up to 100 m.

1000BASE-T SFP transceivers

1000Base-SX SFP Transceivers for Multimode Fiber Only

1000Base-SX SFP is compatible with the IEEE 802.3z 1000BASE-SX standard, operating on legacy 50 um multimode fiber links up to 550m and on 62.5 um multimode fibers up to 220 m. And it can support up to 1 km over laser-optimozed 50 um multimode fiber cable.

1000Base-SX SFP transceiver

1000BASE-LX/LH SFP Transceivers for Both Multimode and Single-Mode Fibers

The 1000BASE-LX/LH SFP, compatible with the IEEE 802.3z 1000BASE-LX standard, operates on standard single-mode fiber optic link spans of up to 10 km, and up to 550 m on any multimode fibers. However, when used 1000BASE-LX/LH SFP over legacy multimode fiber type, the transmitter should be coupled through a mode conditioning patch cable.

1000BASE-LX LH SFP transceiver

1000BASE-EX SFP Transceivers for Long-Reach Single-Mode Fibers

The 1000BASE-EX SFP operates on standard single-mode fiber optic link spans of up to 40 km in length. A 5-dB inline optical attenuator should be inserted between the fiber optic cable and the receiving port on the SFP at each end of the link for back-to-back connectivity.

1000BASE-EX SFP transceiver

1000BASE-ZX SFP Transceivers for Long-Reach Single-Mode Fibers

The 1000BASE-ZX SFP operates on standard single-mode fiber-optic link spans of up to approximately 70 km in length. When shorter distances of single-mode fiber (SMF) are used, it might be necessary to insert an inline optical attenuator in the link to avoid overloading the receiver. A 10-dB inline optical attenuator should be inserted between the fiber optic cable plant and the receiving port on the SFP at each end of the link whenever the fiber optic cable span loss is less than 8 dB.

1000BASE-ZX SFP transceiver

1000BASE-BX10-D and 1000BASE-BX10-U SFP for Single-Fiber Bidirectional Applications

The 1000BASE-BX10-D and 1000BASE-BX10-U SFP transceivers operate on a single strand of standard SMF. A 1000BASE-BX10-D device is always connected to a 1000BASE-BX10-U device with a single strand of standard SMF with an operating transmission range up to 10 km. The following picture shows how to achieve communication over a single stand of fiber: by separating the transmission wavelength of the two devices—1000BASE-BX10-D transmits a 1490-nm channel and receives a 1310-nm signal, whereas 1000BASE-BX10-U transmits at a 1310-nm wavelength and receives a 1490-nm signal. As shown, the presence of a wavelength-division multiplexing (WDM) splitter integrated into the SFP to split the 1310-nm and 1490-nm light paths.

1000BASE-BX10-D and 1000BASE-BX10-U SFP transceivers

CWDM SFP Transceivers

CWDM (Coarse Wavelength-Division Multiplexing) SFP is the type of optical transceiver that involves CWDM technology. Like conventional SFPs, CWDM SFP is also a hot-swappable I/O device that plugs into an SFP port or slot of a switch or router, and links the port to the fiber-optic network. It is a convenient and cost-effective solution for the adoption of Gigabit Ethernet and Fibre Channel (FC) in campus, data-center, and metropolitan-area access networks.


DWDM SFP Transceivers

DWDM (Dense Wavelength-Division Multiplexing) SFP transceivers are used as part of DWDM optical network to provide high-capacity bandwidth across an optical fiber network, which is a high performance, cost effective module for serial optical data communication applications up to 4.25Gb/s. There are 32 fixed-wavelength DWDM SFPs that support the International Telecommunications Union (ITU) 100-GHz wavelength grid. DWDM SFP transceivers provide the high speeds and physical compactness while delivering the deployment flexibility.

DWDM SFP transceivers

How to Install SFP Transceivers to Your System?

Here are some steps for you to follow when installing an SFP transceiver module:

    • Step 1. Remove the SFP transceiver module from its protective packaging (Do not remove the optical bore dust plugs).
    • Step 2. Remember to check the label on the SFP transceiver body to guarantee that you get the correct model for your network.
    • Step 3. Find the send (Tx) and receive (Rx) markings that identify the top side of the SFP transceiver.
    • Step 4. Position the SFP transceiver in front of the socket opening.
    • Step 5. Insert the SFP transceiver into the socket until you feel the SFP transceiver module connector snap into place in the socket connector.


  • Step 6. Remove the dust plugs from the network interface cable LC connectors, and save the dust plugs for future use.
  • Step 7. Remove the dust plugs from the SFP transceiver optical bores.
  • Step 8. Immediately attach the network interface cable LC connector to the SFP transceiver.
  • Step 9. Connect the SFP transceiver to your target device with specific copper or fiber cable.
  • Step 10. Observe the port status LED.

After going through different types of SFP transceivers presented in the article, you may already have a better understanding of SFP optical modules. FS.COM provides a broad range of SFP optical transceivers that are compatible with the major brands in the market, such as Cisco, Juniper, Arista, etc. For more details, please contact us via

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