What is a 400G module? And application scenarios for 400G Modules?

The continuous growth in demand for data centers and cloud computing resources has driven the development of large-scale public cloud data centers. The continuous increase in global data traffic is driving the development of data centers from 100G to higher speeds, larger bandwidth, and lower latency. 400G will be the direction for upgrading and building the next generation of backbone networks, becoming an inevitable trend in data centers. Many service providers have started deploying 400G network construction solutions. In the process of building a 400G network system, the 400G optical module plays a crucial role.

The 400G optical module supports a transmission rate of 400Gbps, which is extremely high and can meet the needs of large-scale data centers and high-performance computing. It was born to adapt to the gradual shift of the network market from 100M, 1G, 25G, and 40G to 100G and 400G, and the 400G optical module plays a crucial role in building a 400G network system. 400G optical modules typically use multiple interface types, including QSFP-DD (quad small pluggable dual density), OSFP (quad small pluggable), and so on. These interface types provide high-density port configurations and increased bandwidth. At present, there is no unified standard for 400G modules, and there are mainly six types of standards and packaging forms for 400G optical modules.








2400G optical module application

The transmission rate of the 400G optical module is 400G, which is four times higher than that of the 100G optical module, and can maximize the bandwidth and port density of the data center.

From the classification of transmission distance, the application of 400G optical modules can be mainly divided into these categories:

1. Transmission distance less than 100 meters

Mainly used for interconnecting servers and switches inside the cabinet. At present, the data rates are mainly 10G and 25G, and are transitioning to 50G or 100G. Generally

Connect directly using AOC active optical cables or DAC high-speed cables.

2. Transmission distance of 500 meters

Mainly used for interconnecting switches within data centers and computer rooms. The data speed is still mainly 40G and 100G, gradually transitioning to 400G. short distance

Mainly using 850nm multimode fibers; Single mode optical fibers with a wavelength of 1310nm are often used for distances ranging from 100m to 500m, but due to cost considerations, they are mainly used

It adopts parallel single-mode technology.

3. Transmission distance less than 10km

Mainly used for interconnecting switches or routers between data center buildings. At present, the data rate is mainly 100G and is transitioning to 400G. Due to transmission distance

Due to the longer distance, the cost of optical fibers is relatively high, so wavelength division multiplexing technology is often used to transmit more signals on a single fiber. For 100G speeds

It is said that the state path communication can provide 100G LR4 optical modules, and the state path communication 100G PSM4 optical module can still be used in scenarios ranging from 500m to 2km.

4. Transmission distance greater than 10km

Mainly used for interconnection between multiple data centers. At present, the implementation method is 100G+DWDM. For a speed of 100, it depends on the data center’s distance mode communication provides a selection of 100G LR4, 100G ER4, and 100G ZR4 optical modules.