It has been a while since we talked about networking on the Bach Seat. So it is time to get back to my roots. Ethernet continues to dominate the world. The Institute of Electrical and Electronics Engineers (IEEE) 802.3 Ethernet Working Group, the group responsible for the Ethernet standard, recently ratified 4 new Ethernet-related standards. The committee approved IEEE 802.3bp, IEEE 802.3bq, IEEE 802.3br, and IEEE 802.3by.
IEEE 802.3br has implications for IoT and connected cars. This new standard addresses the needs of industrial control system manufacturers and the automotive market by specifying a pre-emption methodology for time-sensitive traffic. IEEE 802.3bp addresses how Ethernet operates in harsh environments found in automotive and industrial applications.
The 2 more interesting new standards to networkers are IEEE 802.3bq and IEEE 802.3by. These standards help define how 25 GB and 40 GB Ethernet will work and more importantly how products from multiple vendors should interoperate in the data center. For a summary of the rationale for the new standard here is the IEEE presentation (PDF).
IEEE 802.3bq, “Standard for Ethernet Amendment: Physical Layer and Management Parameters for 25 Gb/s and 40 Gb/s Operation, Types 25GBASE-T and 40GBASE-T“, opens the door to higher-speed 25 Gb/s and 40 Gb/s twisted pair solutions with auto-negotiation capabilities and Energy Efficient Ethernet (EEE) support for data center applications.
IEEE 802.3by, “Standard for Ethernet Amendment: Media Access Control Parameters, Physical Layers, and Management Parameters for 25 Gb/s Operation”, introduces cost-optimized 25 Gb/s PHY specifications for single-lane server and switch interconnects for data centers.
Siemon’s Standards Informant explains that 25GBASE-T will be backward-compatible with existing BASE T technology and both 25GBASE-T and 40GBASE-T are planned for operation over TIA category 8 cabling. The deployment opportunity for 25GBASE-T is aligned with 40GBASE-T and defined as the same 2-connector, 30-meter reach topology supporting data center edge connections (i.e., switch to server connections in row-based structured cabling or top of rack configurations).
The standard’s ratification comes shortly after the Telecommunications Industry Association (TIA) approved its standard specifications for Category 8 cabling, the twisted-pair type designed to support 25GBase-T and 40GBase-T.
Though 25 Gigabit Ethernet is only now becoming an official standard, Enterprise Networking Planet reports that multiple vendors already have technologies in the market. Among the early adopter of 25 GbE is Broadcom (AVGO) which announced back in 2014 that its StrataXGS Tomahawk silicon would support 25 GbE. In 2015, Arista (ANET) announced its lineup of 25 GbE switches. Cisco (CSCO) is also embedding 25 GbE support in some of its switches including the Nexus 9516 switch.
That is where 25-Gb/s Ethernet comes in. It uses the same LC fiber cables and the SFP28 transceiver modules are compatible with standard SFP+ modules. This means that data-center operators can upgrade from 10 GbE to 25 GbE using the existing installed optical cabling and get a 2.5X increase in performance.
The IEEE 25GbE standard seems to have come out of nowhere, (especially considering the L O N G D R A W N O U T 8 0 2 . 1 1 n process but the technology actually came into being as the natural single-lane version of the IEEE 802.3ba 100-Gb/s Ethernet standard. The 100-Gb/s Ethernet standard uses four separate 25-Gb/s lanes running in parallel, so defining a single lane makes it a straightforward and natural subset of the 100-Gb/s standard.
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EEE P802.3by and P802.3bq were initially targeted for server connections in mega data centers like Amazon, Facebook, and Google. In the next 5 years, 25G will be the next mainstream server upgrade from 10G, even for smaller data centers. SMB data centers will be facing a connectivity crisis in the future as the pace of virtualization increases.
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Ralph Bach has been in IT long enough to know better and has blogged from his Bach Seat about IT, careers, and anything else that catches his attention since 2005. You can follow him on LinkedIn, Facebook, and Twitter. Email the Bach Seat here.