According to the leading Cloud Service Providers (CSPs) and various networking forecast reports, 400G Ethernet will emerge as the leading technology since 2020. IDC (International Data Corporation) and Cignal Ai have also proved the similar situation. In short, 400G Ethernet will replace 100G and 200G deployments in a faster way than 100G did to the previous Ethernet.
The factors affecting the development of 400G are mainly application-driven and technology-driven. The application drivers include 5G high-speed transmission, market requirements for data centers, cloud computing, and high-definition video transmission. Technology drivers include development of technologies in the market and product standardization.
5G Accelerates 400G Ethernet: An analysis from Cisco points out that 5G technology needs edge computing architecture, which brings cloud resources—compute, storage and networking—closer to applications, devices and users. While, the edge computing needs more bandwidth, support for more devices on the network, and greater security to protect and manage the data. For example, a 4G radio system can support up to only 2,000 active devices in a square kilometer, while 5G could support up to 100,000 active devices in the same range. With 400G technology offering more bandwidth, more devices and applications could be supported in 5G.
|Average Data Rate||25 Mb/s||100 Mb/s|
|Peak Data Rate||150 Mb/s||10,000 Mb/s|
|Latency||50 ms||1 ms|
|Connection Density||2,000 Per Square Kilometer||100,000 Per Square Kilometer|
Data Center & Cloud Computing Requirements: A research from Cisco indicates that cloud-based data centers will take over 92% of the next-generation data center workload while the traditional data centers will take over less than 8% after 2021. These objective requirements for higher data rates drive 400G development greatly. It is estimated that 400G will be the prevailing speed in switch chips and network platforms in the coming years.
High-Definition Video Transmission Needs: Basically all forms of Internet applications are moving towards video. It is estimated that more than 80% of the traffic is video. Video is a very important platform for everyone to interact in the future, especially real-time video streaming, such as multi-party video conferences. High-definition videos (such as 4K videos) need more bandwidth and less latency compared with the previous normal ones featuring lower definition.
400G technology was originally known as IEEE 802.3bs and was officially approved in December, 2017. It regulates new standards including Forward Error Correction (FEC) to improve error performance. Abide by these standards, early 400G network elements have successfully completed trials and initial deployment. At present, some brand 400G switches have been put into use such as Cisco 400G Nexus, Arista 400G 7060X4 Series, Mellanox Spectrum-2, FS 400G switch, etc. 400G connection scheme is also blooming such as 400G DAC and 400G transceivers (400G QSFP-DD transceiver, 400G OSFP transceiver, 400G CFP8 transceiver, etc.), of which 400G QSFP-DD is becoming the leading form factor for its high density and low power consumption. As 400G Ethernet grows faster to standardization, commercialization and scale, soon 400G product system will be gradually perfect and more 400G products will appear in return.
Compared to the 10G Ethernet, 25G Ethernet gains more popularity in the whole optical transmission industry because 25Gbps and 50Gbps per channel technology provide the basic standards for existing 100G (4x 25Gbps), the coming 400G (8x 50Gbps) and the future 800G network. Therefore, the rapid development of 400G Ethernet will promote the 25G and 100G markets to a certain extent in turn. Similarly, the quick appearance of 400G applications implicates that 200G is a flash in the pan.
For access, metro, and data center interconnection scenarios, where short transmission distance and higher bandwidth are required, fiber resources are relatively scarce. The single-carrier 400G technology can provide the largest transmission bandwidth and the highest spectral efficiency with the simplest configuration, which effectively reduces transmission costs.
In the backbone and some more complex metropolitan area networks, where the transmission distance is longer with more network nodes, the requirements for transmission performance are more stringent. Under such circumstances, dual-carrier technology (2x 200G) and an optimized algorithm could work together to compress the channel spacing. This can not only improve the spectral efficiency by 30% (close to the level of a single-carrier 400G technology), but also extend the transmission distance of 400G Ethernet to several thousand kilometers, helping operators quickly deploy 400G backbone networks with minimum bandwidth resources.
400G solution can also increase the single fiber capacity by 40% and reduce power consumption by 40%, thereby greatly improving network performance and reducing network operation and maintenance costs.
Many suppliers hype their 400G products to get ahead of the curve. Actually, few vendors have the real supply capacity and the quality of most 400G products supplied can't be assured. To win from the fierce market competition, vendors should pay more attention to improving product quality and strong supply capability. And this is indubitably beneficial to users, who can get better products and services with relatively lower prices.
In the multimode installed base, the biggest difference between 100G and 400G modules is the increase in total number of fibers. For single mode transmission system, most of the duplex LC and MPO-based architecture that is deployed at 100G should serve for 400G. For parallel or multi-fiber transmission, transceivers like 400GBASE-SR4.2 operating with short wavelength division multiplexing (SWDM) at four wavelengths provide longer distances over OM5 fiber than OM4 or OM3. And OM5 wideband multimode fiber (WBMMF) will allow use of SWDM technology to transmit multiple signals (wavelengths) on one fiber. This indicates that OM5 fiber and SWDM technologies will continue to offer improved support on 400G Ethernet.
|Data Rate||Transceiver||Pairs||Rated Reach|
400G Ethernet is an inevitable trend in current networking market. Driven by various market demands and technologies, it has come more rapidly than any previous technology. And it also has many significant effects, such as reducing the market share of 200G and saving transmission costs to a certain extent. There are already some mature 400G optics products in the market, such as 400G QSFP-DD transceivers, 400G DACs, as well as 400G DAC breakout cables. And 400G technology is no doubt going to be more and more advanced to promote the developments of 400G Ethernet and 400G applications.