Terabit Ethernet


Terabit Ethernet or TbE is Ethernet with speeds above 100 Gbit/s. 400 Gigabit Ethernet and 200 Gigabit Ethernet standards developed by the IEEE P802.3bs Task Force using broadly similar technology to 100 Gigabit Ethernet were approved on December 6, 2017. In 2016, several networking equipment suppliers were already offering proprietary solutions for 200G and 400G.
The Ethernet Alliance's 2020 technology roadmap expects speeds of 800 Gbit/s and 1.6 Tbit/s become IEEE standard after 2020, possibly between 2023 and 2025. Doubling to 800 GbE is expected to occur after 112 Gbit/s SerDes become available. The Optical Internetworking Forum has already announced five new projects at 112 Gb/s which would also make 4th generation 100 GbE links possible.

History

and Google, among other companies, have expressed a need for TbE. While a speed of 400 Gbit/s is achievable with existing technology, 1 Tbit/s would require different technology. Accordingly, at the IEEE Industry Connections Higher Speed Ethernet Consensus group meeting in September 2012, 400 GbE was chosen as the next generation goal. Additional 200GbE objectives were added in January 2016.
The University of California, Santa Barbara attracted help from Agilent Technologies, Google, Intel, Rockwell Collins, and Verizon Communications to help with research into next generation Ethernet.
As of early 2016, chassis/modular based core router platforms from Cisco, Juniper and other major manufacturers support 400 Gbit/s full duplex data rates per slot. One, two and four port 100GbE and one port 400GbE line cards are presently available. As of early 2019, 200GbE line cards became available after 802.3cd standard ratification.

Standards development

The IEEE formed the "IEEE 802.3 Industry Connections Ethernet Bandwidth Assessment Ad Hoc", to investigate the business needs for short and long term bandwidth requirements.
IEEE 802.3's "400 Gb/s Ethernet Study Group" started working on the 400 Gbit/s generation standard in March 2013. Results from the study group were published and approved on March 27, 2014. Subsequently, the IEEE 802.3bs Task Force started working to provide physical layer specifications for several link distances.
The IEEE 802.3bs standard was approved on December 6, 2017 and is available online.
The IEEE 802.3cd standard was approved on December 5, 2018.
The IEEE 802.3cn standard was approved on December 20, 2019.
The IEEE 802.3cm standard was approved on January 30, 2020.

IEEE project objectives

Like all speeds since 10 Gigabit Ethernet, the standards support only full-duplex operation. Other objectives include:
  1. Support MAC data rates of 400 Gbit/s and 200 Gbit/s
  2. Preserve the Ethernet frame format utilizing the Ethernet MAC
  3. Preserve minimum and maximum frame size of current Ethernet standard
  4. Support a bit error ratio of 10−13, which is an improvement over the 10−12 BER that was specified for 10GbE, 40GbE, and 100GbE.
  5. Support for OTN, and optional support for Energy-Efficient Ethernet.

    802.3bs project

Define physical layer specifications supporting:

400G port types