What is 25G Ethernet?

What is 25G Ethernet?
What is 25G and how does it evolve? What is its future?
A standard for Ethernet network connectivity in a data center environment is 25G Ethernet or 25 Gigabit Ethernet. IEEE P802.3by is created by the Ethernet Task Force of 25 Gb/s. IEEE 802.3by utilizes technology identified as four 25 Gbps channels for 100 Gigabit Ethernet (IEEE 802.3bj).
25G Ethernet technology remains to innovate and pave the way for greater networking speeds in relation to 10, 40 and 100GbE networking. As there is already 40G, it might be question why it appears. Over the years, 40GbE technology has developed and acquired momentum as an alternative for enterprises, service and cloud providers. Since 40G Ethernet technology is four lanes at 10G speed, it does not offer the advantages of reducing power consumption when upgrading to 100G that 25G can provide.
25G Ethernet do provide a cheaper route to 50Gbps, 100Gbps and higher Ethernet rates. Network operators are no longer restricted to use a 40G QSFP port to go from one device to another in order to achieve 100G bandwidth.

25G Ethernet dates back to 2014. This is the year of the first submission of 25G. A wide range of vendors discussed their cost and efficiency during that time compared to 10G, 40G, and 100G. Google, Microsoft, Broadcom, Arista, Mellanox, and other well known data-center and cloud computing providers have formed a special research group, 25G Ethernet Consortium, to promote the standardization of 25G Ethernet.

In 2015, the first production of 25G products appeared on the market. Researchers conducted analyzes of 25G Ethernet from multiple elements, like demands in data centers, benefits, uses and questions from individuals who may be concerned.
The standardization of 25G Ethernet has gradually taken shape with the deepening of research, and providers had high aspirations for its growth.
The members of the 25G Ethernet Consortium, Broadcom, Mellanox and Arista stepped forward and planned to launch their 25G products.
Broadcom increased the output of its "Tomahawk" switch ASICs (Application-Specific Integrated Circuit), and Mellanox announced its Spectrum ASICs and adapters supporting 25 Gb/s, 50 Gb/s and 100 Gb/s.
With its three new switches, the 7060X7260X and 7320X, which support both 25 and 50 Gigabit Ethernet, Arista joins the list of vendors supporting the new 25G Ethernet standards.

Fast 25G growth occurred in 2016-2017 The significance of these two years for 25G Ethernet development is important. Over the years, the IEEE has approved the 802.3by 25G Ethernet specification and other major suppliers are eager to launch their own 25G products to meet the market trend.
With its latest Prestera switches and Alaska Ethernet transceivers, Marvell launched the 25GbE end-to-end data center alternative for the industry in 2016.

Finisar launched 25G Ethernet optics for high-speed data centers with its SFP28 eSR transceiver allowing 300-meter connections to existing OM3 MMF and 25G SFPwire, and Active Optical Cable (AOC) that also offers real-time troubleshooting and performance monitoring.
Server vendors such as Dell, HPE, and Lenovo have solutions for 25G network adapters. Mellanox offered SN2100 with a half-rack width of 16-port 100G and can be used with breakout cables as a 64-port 25G.

25G was acknowledged for next-generation server access rates in 2017. There is an urgent need to finalize the related technical specifications such as 25G ToR switches and AOC wires, and worldwide organisations are working aggressively to take the action.
As companies are increasingly offering different types of 25G SFP28 transceivers, DACs, and AOCs, the request for the construction of 25G Ethernet is increasing.

In 2018 25G products compete with other products. Sales of 10G commodities decreased over the year while more and more recognition was given to 25G products.
With the new 25G Ethernet server and storage solutions, Supermicro opened the road to 100G networking.
Supermicro also provides SBM-25G-100, a 25G switch which has twenty 25G downlinks, four QSFP28 ports where either 40G or 100G uplink connections can be configured for each port.

25G is currently used primarily for switch-to-server apps. And in some aspects it gets ground compared to 10G and 40G Ethernet. With a five-year forecast by industry analysts at the Dell'Oro Group, you can see clear trends in the 25G market.
Since 25G switch offers a more convenient way to migrate to 100G or 400G network in a considerable time, it's demand will go further.