400G QSFP-DD Transceiver Types and Fiber Connections

Updated on Apr 19, 2022 by

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400G QSFP has become one of the most popular form factors in the next-generation network. And different types of modules have appeared in the 400G optical transceiver market. What are 400G QSFP-DD transceiver types? What fiber optic cables could be used with these 400G optical modules? What about the answers to frequently asked questions about 400G QSFP? This post will illustrate them thoroughly.

400G QSFP-DD Transceiver Types

400G QSFP transceivers are introduced respectively in the following table according to the two transmission types (over multimode fiber and single-mode fiber) they support.

Transmission Type	QSFP-DD Product Description	Reach	Optical Connector	Wavelength	Optical Modulation	Protocol
Multimode fiber	400G QSFP-DD SR8	up to 100m over OM4 up to 70m over OM3	MPO-16	850nm	50G PAM4	IEEE 802.3cd
Multimode fiber	400G QSFP-DD SR4.2	up to 150m over OM5 up to 70m over OM3	MPO-12	850nm	50G PAM4	IEEE 802.3
Single-mode fiber	400G QSFP-DD DR4	up to 500m over parallel SMF	MPO-12	1310nm	50G PAM4	IEEE 802.3bs
	400G QSFP-DD 4x 100G-DR	up to 500m over parallel SMF	MPO-12	1310nm	50G PAM4	IEEE 802.3bs
	400G QSFP-DD XDR4/DR4+	up to 2km over parallel SMF	MPO-12	1310nm	50G PAM4	IEEE 802.3bs
	400G QSFP-DD FR4	up to 2km over parallel SMF	LC	CWDM4 wavelength	50G PAM4	100G Lambda MSA
	400G QSFP-DD 4x 100G-FR	up to 2km over parallel SMF	MPO-12	1310nm	50G PAM4	IEEE Std 802.3
	400G QSFP-DD LR4L	up to 6km over parallel SMF	LC	1310nm	50G PAM4	IEEE 802.3bs
	400G QSFP-DD 4x 100G-LR	up to 10km over parallel SMF	MPO-12	1310nm	50G PAM4	IEEE 802.3cu
	400G QSFP-DD LR4	up to 10km over parallel SMF	LC	CWDM4 wavelength	50G PAM4	100G Lambda MSA
	400G QSFP-DD LR8	up to 10km over parallel SMF	LWDM wavelength	CWDM4 wavelength	50G PAM4	IEEE 802.3bs
	400G QSFP-DD ER8	up to 40km over parallel SMF	LWDM wavelength	1310nm	50G PAM4	IEEE 802.3cn

Fiber Connections for 400G QSFP Transceivers

400G QSFP-DD SR8

A QSFP-DD SR8 can interop with another QSFP-DD SR8 over an MPO-16 cable. This is the most popular connection using an MPO-16 cable to connect two QSFP-DD SR8 transceivers directly.

400G QSFP-DD SR8

400G QSFP-DD SR8 breaks out to 2× 200G SR4.

QSFP-DD SR8 interops with 8× 50G SR over MPO-16 to 8× duplex LC fiber cables.

400G QSFP-DD SR4.2

A QSFP-DD SR4.2 interops with another QSFP-DD SR4.2 over an MPO-12 trunk cable.

400G QSFP-DD SR4.2

400G QSFP-DD DR4

QSFP-DD DR4 interops with QSFP-DD DR4 over an MPO-12 trunk cable.

400G QSFP-DD DR4 interops with 4× 100G DR over MPO-12 to 4× duplex LC breakout cable.

400G QSFP-DD 4x 100G-DR

QSFP-DD DR4-Si interops with QSFP-DD DR4-Si over an MPO-12 trunk cable.

400G QSFP-DD 4x 100G-DR

400G QSFP-DD DR4-Si interops with 4× 100G DR over MPO-12 to 4× duplex LC breakout cable.

400G QSFP-DD XDR4/DR4+

QSFP-DD XDR4/DR4+ interops with QSFP-DD XDR4/DR4+ over an MPO-12 trunk cable.

400G QSFP-DD XDR4/DR4+

400G QSFP-DD XDR4 interops with 4× 100G FR modules over an MPO-12 to 4× duplex LC cable.

400G QSFP-DD FR4

QSFP-DD FR4 interops with QSFP-DD FR4 over a duplex LC cable.

400G QSFP-DD 4x 100G-FR

QSFP-DD FR-Si interops with QSFP-DD FR-Si over an MPO-12 trunk cable.

400G QSFP-DD FR-Si interops with 100G FR over an MPO-12 to 4× duplex LC cable.

400G QSFP-DD LR4L

QSFP-DD LR4L interops with QSFP-DD LR4L over an duplex LC cable.

400G QSFP-DD 4x 100G-LR

QSFP-DD PR4L interops with QSFP-DD PR4L over an duplex LC cable.

400G QSFP-DD PR4L interops with 4x 100G LR modules over an MPO-12 to 4x duplex LC cable.

400G QSFP-DD LR4

QSFP-DD LR4 interops with QSFP-DD LR4 over an duplex LC cable.

400G QSFP-DD LR8

QSFP-DD LR8 interops with QSFP-DD LR8 over an duplex LC cable.

400G QSFP-DD ER8

QSFP-DD ER8 interops with QSFP-DD ER8 over an duplex LC cable.

Key Benefits of 400G Data Center

The storage and computing requirements supported by data centers present new challenges to connectivity within the data center, in terms of bandwidth, transmission distance, power consumption and cost. However, 400G data center can provide high Density, low power consumption and flexible deployment.

400G QSFP Transceivers: Q&A

Q: What does "SR8", "DR4", "XDR4", "FR4", "LR4", and "LR8" mean in QSFP 400G modules?

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 a QSFP-DD transceiver module into an OSFP port?

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

Q: Can I plug a 100G QSFP28 module into a 400G QSFP port?

A: Yes. A QSFP28 module can be inserted into a QSFP-DD port (without a mechanical adapter). When using a QSFP28 module in a QSFP-DD port, the QSFP-DD port must be configured for a data rate of 100G instead of 400G.

Q: What other breakout options are possible apart from using the 400G QSFP-DD modules mentioned above?

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

Conclusion

According to the related report, the global 400G optical transceiver market is expected to be at $22.6 billion in 2023. Next generation optical transceiver devices use less power, are less expensive, and are smarter and smaller. let's grab the chance to learn more about the 400G QSFP-DD, 400G QSFP112 and 400G OSFP optical transceiver to get the professional 400G products guidelines.