IEEE 802.3bz, NBASE-T and MGBASE-T are standards for Ethernet over twisted pair at speeds of 2.5 and 5 Gbit/s. These use the same cabling as the ubiquitous Gigabit Ethernet, yet offer higher speeds. The resulting standards are named 2.5GBASE-T and 5GBASE-T.[1][2][3]
NBASE-T refers to Ethernet equipment that can automatically negotiate to operate at speeds of 100 Mbit/s, 1, 2.5, 5, or 10 Gbit/s, depending on the quality of the cable and the capabilities of the equipment at the other end of the cable.[citation needed]
Technology
These standards are specified in Clauses 125 and 126 of the IEEE 802.3 standard. The physical (PHY) layer transmission technology of IEEE 802.3bz is based on 10GBASE-T, but operates at a lower signaling rate. By reducing the original signal rate to 1⁄4 or 1⁄2, the link speed drops to 2.5 or 5 Gbit/s, respectively.[4] The spectral bandwidth of the signal is reduced accordingly, lowering the requirements on the cabling, so that 2.5GBASE-T and 5GBASE-T can be deployed at a cable length of up to 100 m on Cat 5e or better cables.[5]
The NBASE-T effort also standardized how its switches can implement power over Ethernet according to the IEEE 802.3at and successor standards. This allows a single cable to provide both power and data for high-bandwidth wireless access points such as those that implement the 802.11ac and 802.11ax standards.[6]
History
As faster WiFi protocols such as IEEE 802.11ac were developed, there was significant demand for cheap uplinks faster than 1000BASE-T. These speeds became relevant around 2014 as it became clear that it would not be possible to run 10GBASE-T over already widely-deployed Cat5e cable. IEEE 802.3bz also supports Power over Ethernet, which had previously not been available at 10GBASE-T.
As early as 2013, the Intel Avoton server processors integrated 2.5 Gbit/s Ethernet ports.
Whilst Broadcom had announced a series of 2.5 Gbit/s transceiver ICs,[7] 2.5 Gbit/s switch hardware was not widely commercially available at that point. Many early 10GBASE-T switches, particularly those with SFP+ interfaces, do not support the intermediate speeds.
In October 2014, the NBASE-T Alliance was founded,[8][9] initially comprising Cisco, Aquantia, Freescale, and Xilinx. By December 2015, it contained more than 45 companies, and aimed to have its specification compatible with 802.3bz.[10] The competing MGBASE-T Alliance, stating the same faster Gigabit Ethernet objectives, was founded in December 2014.[11] In contrast to NBASE-T, the MGBASE-T said that their specifications would be open source.[12] IEEE 802.3's "2.5G/5GBASE-T Task Force" started working on the 2.5GBASE-T and 5GBASE-T standards in March 2015.[13] The two NBASE-T and MGBASE-T Alliances ended up collaborating.[14] with the forming of the IEEE 802.3bz Task Force under the patronage of the Ethernet Alliance in June 2015.
On September 23, 2016, the IEEE-SA Standards Board approved IEEE Std 802.3bz-2016.[15]
References
- ^ "IEEE P802.3bz 2.5G/5GBASE-T Task Force". IEEE Standards Association.
- ^ "New IEEE P802.3bz™ Project Achieves Significant Milestone Towards Enabling Higher Speeds Over Installed Base of Twisted Pair Cabling". IEEE Standards Association.
- ^ "IEEE's 802.3BZ Task Force Mediates MGBASE-T and NBASE-T Alliances". Planetech USA. Archived from the original on 2015-11-22. Retrieved 2015-11-22.
- ^ "Cisco Live BRKCRS-3900, slide 41, time 57:40". Archived from the original on 2016-03-03. Retrieved 2016-01-15.
- ^ Clause 126.7.2 of IEEE 802.3-2018
- ^ "Cisco Multigigabit Technology". Retrieved 2020-07-30.
- ^ "Broadcom Announces New High-Performance Multi-Rate Gigabit PHYs". Archived from the original on 2015-05-29. Retrieved 2015-05-28.
- ^ "Industry Leaders Form NBASE-T Alliance to Promote Multi-Gigabit Ethernet Technology for Enterprise Wired and Wireless Access Networks" (Press release). 2014-10-28. Retrieved 2020-07-30.
- ^ "The NBASE-T Alliance℠". NBASE-T Alliance, Inc. Retrieved 30 December 2015.
- ^ "Oh What a Year!". NBASE-T Alliance, Inc. 2015-12-17. Retrieved 2021-02-04.
- ^ "Open Industry Alliance and IEEE to Bring 2.5G and 5G Ethernet Speeds to Enterprise Access Points" (Press release). Retrieved 2020-07-30.
- ^ "Want 2.5G/5G BASE-T Connections? They're coming". Retrieved 2020-07-30.
- ^ "IEEE 802.3bz Project PAR" (PDF). IEEE 802.3bz Task Force. Retrieved 2015-09-22.
- ^ "IEEE's 802.3BZ Task Force Mediates MGBASE-T and NBASE-T Alliances". Archived from the original on 2015-11-22. Retrieved 2015-11-22.
- ^ "[802.3_NGBASET] FW: Approval of IEEE Std 802.3bz 2.5GBASE-T and 5GBASE-T". IEEE P802.3bz Task Force. Retrieved 2016-09-24.
External links
- IEEE P802.3bz 2.5G/5GBASE-T Task Force
- NBASE-T Alliance
- MGBASE-T Alliance