400 Gb Ethernet Standards
Birds on a wire
400 Gb Ethernet Standards

By shellatreille | returnsyourgazeart | 24 Jan 2020

400 Gb Ethernet Standards

By Shelley M. Latreille

This is a report that I wrote for my Wireless Networking class.

Birds on a wire

Ethernet standards are constantly being developed.  The latest standard is 400 Gb Ethernet.  The IEEE (Institute of Electrical and Electronics Engineers) has been making progress with ratifying standards for 400 Gb Ethernet.  In 1983, the IEEE established the 802.3 Ethernet Working Group.  Since its beginning, this group has been developing standards ahead of scheduled requirements.  They are currently working on projects for 400 Gb Ethernet.  There is a linear Ethernet evolution and 400 Gb Ethernet is this evolution’s next step.  Increased Ethernet speeds, along with different levels of speed, are being created to meet the demands of the different Ethernet environments (Hernandez, 2019). 

Ethernet was originally invented to provide support and connections between computers, printers, servers, and devices inside a LAN (Local Area Network).  Since its invention, Ethernet has become much more capable.  Ethernet can support and connect a plethora of technology, including, but not limited to, cellular backhaul, smart meters, power infrastructure, personal medical devices, subscriber access, connected cars, and IoT (Internet of Things).  The 802.3 Ethernet Working Group is working on standardizing 400 Gb Ethernet, along with other speeds, including 2.5 Gb, 5 Gb, 25 Gb, and 50 Gb.  Faster and faster rates are being standardized, along with the Ethernet environment’s new demands and evolving applications (Hernandez, 2019).

In 2014, the IEEE’s Working Group began work solely on 400 Gb Ethernet, which included multimode and single-mode fiber.  Single-mode fiber uses PAM4 (Pulse Amplitude Modulation 4).  400GBASE-SR16 could cover approximately 100 m over multimode fiber through 16 transmit and 16 receive fibers.  Each one was transmitting at 25 Gbps.  This caused the formation of a research group that studied whether OM5 fiber and shortwave WDM (Wavelength Division Multiplexing) technology could reduce the number of required fibers.  400GBASE-DR4 could cover approximately 500 m over single-mode fiber.  It used four parallel fibers in every direction and had a 100 Gbps transmission on every fiber.  400GBASE-FR8 used eight-wavelength WDM to reach at least 2 km over a single-mode fiber in every direction.  400GBASE-LR8 is very similar to FR8, but it can reach out to at least 10 km over single-mode fiber.  All these optical designs are supported by the 8-lane 400GAUI-8 and the 16-lane 400GAUI-16 electrical interfaces.  This group’s work faced delays because it was also tasked with drafting the single-mode fiber specifications for 200 Gb Ethernet in 2016.  Single-mode 200 Gb Ethernet could be based on variations of 400 Gb Ethernet specifications (Hardy, 2018). 

The IEEE created its first Ethernet Roadmap in 2015.  The Ethernet Roadmap displayed all the completed, in-progress, and proposed speeds for Ethernet.  At the time of the Roadmap’s creation, 2.5 Gb, 5 Gb, 25 Gb, and 400 Gb Ethernet speeds were being developed.  Standards for 50 Gb and 200 Gb Ethernet speeds were supposed to be completed between 2018 and 2020.  The Ethernet Roadmap created in 2018 shows that all these standards are now complete.  400 Gb Ethernet speeds were announced in January 2018.  They were demonstrated at the OFC (Optical Fiber Communications) Conference in 2018 (Rowe, 2018).

On December 06th, 2017, Standard 802.3bs, which is the "Standard for Ethernet Amendment: Media Access Control Parameters, Physical Layers, and Management Parameters for 200 gigabit per second (Gb/s) and 400 Gb/s Operation," received full ratification (Hardy, 2018).  It was published during the beginning of 2018.  It took approximately five years for this standard to get published.  This standard outlined details for 200 Gb and 400 Gb Ethernet.  It will assist with all the increasing and diverse bandwidth requirements, along with all costs and applications associated with these requirements.  This standard will make sure that Ethernet will continue to support the increasing demand for higher bandwidth, along with providing support to industry growth and expansion (McLaughlin, 2019).

In December 2018, the IEEE approved the 802.3cd standard.  This standard is currently being worked on.  This standard outlines details for 50 Gb, 100 Gb, and 200 Gb Ethernet.  It will provide cost-effective solutions for interconnecting servers in data centers.  Signaling technology for 50 Gb and 100 Gb Ethernet will be re-evaluated.  Increased bandwidth and higher speed processing are needed because servers that virtualize more applications are driving increased bandwidth into the network.  Network uplinks must have the capability for high speeds so that they will match server speeds.  200 Gb Ethernet can support network infrastructure and oversubscription rates as servers transfer from 25 Gb to 50 Gb Ethernet.  This would also enable data center fabric topology (McLaughlin, 2019). 

Standard P802.3cn will provide 50 Gb, 200 Gb, and 400 Gb Ethernet over single-mode fiber.  This standard is at the top of the IEEE’s list and is currently being worked on.  It will influence PAM4 technology.  It will support links at the current rate of 10 km and increase them so that they will reach up to 40 km.  Standard P802.3ct will provide 100 Gb and 400 Gb Ethernet over DWDM (Dense Wavelength Division Multiplexing) Systems.  This standard will allow Ethernet to reach up to 80 km over a DWDM System.  It can be used for future mobile aggregation and core backhaul.  The most significant drivers for this standard are MSOs (Multi-Service Operators) and DCI (Data Center Interconnect).  There is a group working on a 100G PAM4 on four separate lambdas, including one at 500 m and one at 2 plus km.  Another group is working on 100G electrical.  An 802.3ct Task Force will be formed and will work on 80 km solutions for 100 Gb and 400 Gb DWDM (McLaughlin, 2019).

The IEEE is currently working on an Ethernet bandwidth assessment.  The goal of this assessment is to understand the future needs of Ethernet and to ensure those needs are met.  Bandwidth demand is being reviewed relative to application spaces and market timing.  The goal is to create a forecast out to 2025.  They are also working on a project called the New Ethernet Applications Ad Hoc.  This project’s goals are to evaluate requirements for new Ethernet-based applications, detect gaps that aren’t being addressed by 802.3 standards, and to expedite the creation of industry unanimity towards plans to begin the creation of new standards (D’Ambrosia and Gorshe, 2019).

The IEEE works hard to make sure that all the wired infrastructure behind wireless applications will be ready and able to support all current and future innovations and technological needs.  The IEEE works continuously to transform and revolutionize 802.3 Ethernet.  Market needs continue to evolve, which causes needs for increasingly higher bandwidth.  Ethernet must have continual enhancements, which means that current Ethernet standards must be evolved, and new standards must be written to keep up with demand, innovation, and technology.  Wireless applications drive current and future growth factors, which means that they have a significant impact on 802.3 Ethernet wired infrastructure (D’Ambrosia and Gorshe, 2019).




D’Ambrosia, J. and Gorshe, S. (2019, November 12). Innovating the wires behind wireless connectivity.

          Retrieved from RCR Wireless News:



Hardy, S. (2018, January 04). Ethernet Alliance salutes approval of IEEE 802.3bs 200 Gigabit Ethernet,

400 Gigabit Ethernet standard. Retrieved from Lightwave:




Hernandez, D. (2019, April 06). Ethernet Standardization Evolution Will Be Far from Linear.

          Retrieved from Versa Technology:



McLaughlin, P. (2019, March 01). The Road Beyond 200G. Retrieved from Cabling Installation &

          Maintenance: https://www.cablinginstall.com/data-center/high-speed-cabling/article/16466593/the-



Rowe, M. (2018, September 10). 400G Ethernet is Here, as are Other Speeds. Retrieved from EE Times:



Artist, Photographer, Writer, Creative Innovator, Website Designer / Web Developer in West Jordan, Utah . I enjoy learning new things, traveling to historic, paranormal, and abandoned locations, rock hounding, museums, technology, and the abstract.


This blog will showcase my photography, art, short stories, and poetry. It will be abstract and colorful. My website: www.ReturnsYourGazeArt.com

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