How Much Do You Know About 400G OSFP Transceiver?

Updated on Jun 16, 2022 by


Data centers support the IT infrastructure needed to run data-intensive applications and their ever-growing demand for storage. From remote work and streaming entertainment to decentralized finance and the connected devices that make up the Internet of Things, the need for 400G technology is here and the leap to 800G will be realized with small form factor pluggables such as OSFP.

What is OSFP transceiver optics?

The OSFP (octal small form factor pluggable) is a type of transceiver that connects a network device, such as a switch, to fiber or copper cable, which consists of 8 electrical lanes, running at 50Gb/s each, for a total of the bandwidth of 400Gb/s. This post will give an introduction to 400G OSFP transceiver types, the fiber connections, and some QAs about OSFP.

400G OSFP Transceiver Types

Below lists some current main 400G OSFP transceiver types: OSFP SR8, OSFP DR4, OSFP DR4+, OSFP LR8, OSFP FR4, OSFP 2*FR4, and OSFP LR4, which summarize OSFP transceiver according to the two transmission types (over multimode fiber and single-mode fiber) they support.

Transmission Type OSFP Product Description Reach Optical Connector Wavelength Optical Modulation Protocol
Multimode fiber 400G OSFP SR8 up to 100m over parallel MMF MTP-16/MPO-16 850nm 50G PAM4 IEEE P802.3cm;IEEE 802.3cd
Single-mode fiber 400G OSFP DR4 up to 500m over parallel SMF MTP-12/MPO-12 1310nm 100G PAM4 IEEE 802.3bs
400G OSFP XDR4/DR4+ up to 2km over parallel SMF MTP-12/MPO-12 1310nm 100G PAM4 /
400G OSFP FR4 up to 2km over duplex SMF LC CWDM4 wavelength 100G PAM4 100Glambda MSA
400G OSFP 2FR4 up to 2km over duplex SMF CS CWDM4 wavelength 50G PAM4 IEEE 802.3bs
400G OSFP LR4 up to 10km over duplex SMF LC CWDM4 wavelength 100G PAM4 100Glambda MSA
400G OSFP LR8 up to 10km over duplex SMF LC 1310nm 50G PAM4 OSFP MSA, CMIS Rev 4.0, IEEE 802.3bs

Fibers Connections for 400G OSFP Transceivers


Figure 1 OSFP SR8 to OSFP SR8.jpg

    • 400G OSFP SR8 to 2× 200G SR4 over MTP-16 to 2× MPO-8 breakout cable.

Figure 2 OSFP SR8 to 2 200G SR4.jpg

    • 400G OSFP SR8 to 8× 50G SFP via MTP-16 to 8× LC duplex breakout cable with up to 100m.

Figure 3 OSFP SR8 to 8 50G SFP.jpg


  • 400G OSFP DR4 to 400G OSFP DR4 over an MTP-12/MPO-12 cable.

    Figure 1 OSFP SR8 to OSFP SR8.jpg
  • 400G OSFP DR4 to 4× 100G DR4 over MTP-12/MPO-12 to 4× LC duplex breakout cable.

Figure 4 OSFP DR4 to 4 100G DR.jpg


  • 400G OSFP DR4+ to 400G OSFP DR4+ over an MTP-12/MPO-12 cable.

  • 400G OSFP DR4+ to 4× 100G DR over MTP-12/MPO-12 to 4× LC duplex breakout cable.

Figure 5 OSFP DR4+ to 4 100G DR.jpg


400G OSFP FR4 to 400G OSFP FR4 over duplex LC cable.

Figure 6 OSFP FR4 to OSFP FR4.jpg

400G OSFP 2FR4

OSFP 2FR4 can break out to 2× 200G and interop with 2× 200G-FR4 QSFP transceivers via 2× CS to 2× LC duplex cable.


400G OSFP LR8 to 400G OSFP LR8 over duplex LC cable.


FAQ about 400G OSFP Transceiver

Q: How does the OSFP address the thermal need?

A: The OSFP includes an integrated heatsink, which increases thermal efficiency and allows modules with up to 15W of power to be installed in a switch chassis with conventional airflow.

Q: What about QSFP backward compatibility?

A: Because the OSFP is somewhat broader and deeper than the QSFP, an adapter that supports current 100G QSFP optical modules in an OSFP cage may be built. Backward compatibility is provided via an OSFP to QSFP adaptor.

Q: What does "SR8", "DR4", "XDR4", "FR4", and "LR4" mean?

A: "SR" refers to short range, and "8" implies there are 8 optical channels. "DR" refers to 500m reach using single-mode fiber, and "4" implies there are 4 optical channels. "XDR4" is short for "eXtended reach DR4". And "LR" refers to 10km reach using single-mode fiber.

Q: Can I plug an OSFP transceiver module into a QSFP-DD port?

A: No. QSFP-DD and OSFP are totally different form factors. For more information about QSFP-DD transceivers, you can refer to 400G QSFP-DD Transceiver Types Overview. You can use only one kind of form factor in the corresponding system. E.g., if you have an OSFP system, OSFP transceivers and cables must be used.

Q: Can I plug a 100G QSFP28 module into an OSFP port?

A: Yes. A QSFP28 module can be inserted into an OSFP port but with an adapter. When using a QSFP28 module in an OSFP port, the OSFP port must be configured for a data rate of 100G instead of 400G.

Q: What other breakout options are possible apart from using OSFP modules mentioned above?

A: OSFP 400G DACs & AOCs are possible for breakout 400G connections. See 400G Direct Attach Cables (DAC & AOC) Overview for more information about 400G DACs & AOCs.


400G OSFP transceiver provides a good solution for 400Gbps optical deployments in data centers and broadband access connectivity. More and more 400G OSFP transceivers are continuously introduced to the market, and mass production is gradually realized. It will meet rapidly growing customer demand for analytics, machine learning, and content delivery applications.

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