Overview of 400G QSFP-DD Types and Connection Solutions

NADDOD Holly Fiber Optic Technician Supervisor Jul 28, 2023

With its high speed, compact size, and hot-pluggable advantages, QSFP-DD packaging has gained popularity in the 400G realm. Among the next-generation data center network interconnects, 400G QSFP-DD optical transceivers have become one of the most sought-after options.

 

As 400G becomes standardized, various manufacturers and suppliers have developed different types of 400G QSFP-DD transceivers, such as NADDOD's high-volume 400G QSFP-DD SR8. This article will focus on introducing the types of 400G QSFP-DD optical transceivers and their connection solutions to help you better deploy your network.

 

Complete List of 400G QSFP-DD Optical Transceiver Types

The types of 400G QSFP-DD optical transceivers include 400G QSFP-DD SR8, 400G QSFP-DD DR4, 400G QSFP-DD FR4, 400G QSFP-DD LR4, and 400G QSFP-DD LR8. See the table below for details:

Type

Max Reach

Wavelength

Fiber Optic

Connector

Modulation

Protocol

400G QSFP-DD SR8

100m(OM4) 70m(OM3)

850nm

Multi-mode Fiber

MPO/MTP-16

50G

PAM4

IEEE P802.3cm/IEEE

802.3bs

400G QSFP-DD DR4

500m

1310nm

Single-mode Fiber

MPO/MTP-12

100G

PAM4

IEEE 802.3bs

400G QSFP-DD

XDR4/DR4+

2km

1310nm

Single-mode Fiber

MPO/MTP-12

100G

PAM4

/

400G QSFP-DD FR4

2km

CWDM4 wavelegnth

Single-mode Fiber

LC

100G

PAM4

100G lambda

(MSA)

400G QSFP-DD

2FR4(FR8)

2km

CWDM4 wavelegnth

Single-mode Fiber

CS

50G

PAM4

IEEE 802.3bs

400G QSFP-DD LR4

10km

CWDM4 wavelegnth

Single-mode Fiber

LC

100G

PAM4

100G lambda

400G QSFP-DD LR8

10km

1310nm

Single-mode Fiber

LC

50G

PAM4

IEEE 802.3bs

 

Among them, "SR" refers to the use of multimode fiber to achieve transmission distances of 70 meters, 100 meters, or 150 meters. The "8" indicates that the transceiver has 8 fiber channels. "DR" refers to the use of single-mode fiber to achieve a transmission distance of 500 meters, and the "4" indicates that the transceiver has 4 fiber channels. "XDR4" is an extended version of "DR4." "FR" refers to the use of single-mode fiber to achieve a transmission distance of 2 kilometers, and "LR" refers to the use of single-mode fiber to achieve a transmission distance of 10 kilometers.

 

Common Connection Solutions for 400G QSFP-DD Optical Transceivers

400G QSFP-DD SR8

As mentioned earlier, the 400G QSFP-DD SR8 enables 400G transmission through a multimode fiber, with a maximum distance of 100 meters (OM4). Therefore, the 400G QSFP-DD SR8 transceiver is suitable for short-distance interconnects or multi-channel data communication. The common connection solutions are as follows:

 

400G Interconnects

Two 400G QSFP-DD SR8 transceivers can be connected through MPO/MTP-16 fiber patch cords to achieve 400G transmission.

400G QSFP-DD SR8

 

Multi-Channel Data Communication

① The 400G QSFP-DD SR8 optical transceiver can be connected to the opposite end's 200G SR4 transceiver through an MPO/MTP-16 to 2*MPO/MTP-8 fiber patch cord.

 

② The 400G QSFP-DD SR8 optical transceiver can be connected to the opposite end's 50G SFP transceiver through a 16-core MPO/MTP to 8*LC duplex branch fiber patch cord.

 

400G QSFP-DD DR4

The 400G QSFP-DD DR4 optical transceiver supports a transmission distance of up to 500 meters and can interconnect with 100G DR optical transceivers. It is suitable for short-distance interconnects between 400G and 100G. The 400G QSFP-DD DR4 module can be connected to the opposite end's 100G DR optical module through an MPO-12 to 4*LC duplex branch fiber patch cord.

400G QSFP-DD DR4

 

400G QSFP-DD XDR4/DR4+

The 400G QSFP-DD XDR4/DR4+ is an extended version of the 400G QSFP-DD DR4 and can interconnect with 100G FR. It can be connected to the opposite end's 100G FR module through an MPO-12 to 4*LC duplex branch fiber patch cord.

400G QSFP-DD XDR4

 

400G QSFP-DD FR4

The 400G QSFP-DD FR4 utilizes non-cooled EML lasers with four CWDM wavelengths, achieving a rate of up to 106.25Gbps on a single wavelength based on PAM4 modulation. It is suitable for 400G interconnects. Two 400G QSFP-DD FR4 modules can be interconnected through LC duplex fiber patch cords to achieve 400G interconnectivity.

400G QSFP-DD FR4

 

400G QSFP-DD FR8

The 400G QSFP-DD FR8 optical transceiver (also known as the 400G QSFP-DD 2FR4 optical transceiver) is a 2*200G transceiver. Unlike the 400G QSFP-DD FR4, the 400G QSFP-DD FR8 adopts 50G PAM4 modulation technology and provides eight fiber channels. It is suitable for multi-channel data communication. Typically, the 400G QSFP-DD FR8 can be connected to the opposite end's 200G FR4 optical transceiver through a 2CS to 2*LC duplex branch fiber patch cord.

 

Summary

Whether building large-scale data centers or conducting high-speed data transmission, 400G QSFP-DD optical transceivers are a crucial technology that provides essential support for network communication. By understanding the characteristics and connection solutions of different optical transceivers, we can better meet various network requirements and achieve efficient and reliable data transmission and communication.

 

As a leading provider of comprehensive optical network solutions, NADDOD is committed to delivering innovative, efficient, and reliable products, solutions, and services to users. We offer high-quality 400G QSFP-DD optical transceivers to drive the development of the digital era.