Tag Archives: 25g switch

25G Ethernet – How It Develops and What’s the Future of It?


Have you ever heard of 25G Ethernet? It is a hot topic which is often mentioned these days. Then, what is it and how it develops? What’s the future of it? Let’s find all the answers together in the following text focusing on the developing process of 25G Ethernet.

What Is 25G Ethernet? Why Does It Appear?

25G Ethernet, or 25 Gigabit Ethernet, is a standard for Ethernet network connectivity in a data center environment. It is developed by IEEE P802.3by 25 Gb/s Ethernet Task Force. The IEEE 802.3by standard uses technology defined for 100 Gigabit Ethernet implemented as four 25 Gbps lanes (IEEE 802.3bj).

25G Ethernet to 100G

In addition to 10, 40 and 100GbE networking, 25G Ethernet technology continues to innovate and lay a path to higher networking speeds. Then, you may ask why it appears since we already have 40G. As you may know that 40GbE technology has evolved over the years and has gained some momentum as an option for enterprises, service providers and cloud providers. However, since the underlying technology for 40G Ethernet is simply four lanes at 10G speed, it does not offer the advantages in power consumption reduction when upgrading to 100G, which 25G can offer.

25G Ethernet can provide a simpler path to Ethernet speeds of 50Gbps, 100Gbps and beyond. With 25G, network operators are no longer forced to use a 40G QSFP port to go from one individual device to another to achieve 100G throughput.

Development of 25G Ethernet

Year 2014 – 25G Was First Introduced

The 25G Ethernet can be dated back to 2014. This is the year when 25G was first put forward. At that time, its cost and efficiency were discussed by a wide range of vendors when compared with 10G, 40G, and 100G. Some well-known hyper-scale data center and cloud computing providers such as Google, Microsoft, Broadcom, Arista, Mellanox, etc. have formed a special research group, namely 25G Ethernet Consortium, to explore the standardization of 25G Ethernet and promote the development of it.

Year 2015 – The First Batch of 25G Products Appeared

Stepping into the second year on 25G Ethernet exploration, the Consortium had a deeper and more comprehensive analysis of it. Researchers were conducting analysis of 25G Ethernet from various aspects, such as its demanding trends in data centers, advantages and applications, Q&As people may concern, etc. With the deepening of exploration, the standardization of 25G Ethernet has gradually taken shape, and suppliers have great expectations for the development of it.

As the initiators of the 25G Ethernet Consortium, Broadcom, Mellanox and Arista have stepped ahead of time and planned to launch their products for 25G development. Broadcom was ramping up production of its “Tomahawk” switch ASICs, and Mellanox had announced its Spectrum ASICs as well as adapter cards to support 25 Gb/s, 50 Gb/s, and 100 Gb/s speeds on servers. While, Arista joins list of vendors that are supporting the new 25G Ethernet standards with its three new switches, the 7060X, 7260X and 7320X, that support both 25 and 50 Gigabit Ethernet.

Year 2016-2017 – Fast Development of 25G

These two years have significant meaning for 25G Ethernet development. During the years, the IEEE approved the 802.3by specification for 25G Ethernet and other major suppliers are rushing to launch their own 25G products to comply with the market trend. 25G Ethernet has more practical applications in the data center.

802.3by specification for 25G Ethernet

In 2016, Marvell introduced industry’s most optimized 25GbE end-to-end data center solution with its newest Prestera switches and Alaska Ethernet transceivers. And Finisar introduced 25G Ethernet optics for high speed data centers with its SFP28 eSR transceiver enabling 300-meter links over existing OM3 MMF, and 25G SFPwire, an Active Optical Cable (AOC) with embedded technology that provides real-time troubleshooting and link performance monitoring as well. In addition, major server vendors including Dell, HPE, and Lenovo have 25G network adapters solutions. And as one of the members of 25G Ethernet Consortium, Mellanox offered SN2100 with 16-port 100G half rack width and can be used as 64-port 25G with breakout cables.

In 2017, 25G was recognized as the industry standard for next-generation server access rates. The related technical specifications such as 25G ToR switches and AOC cables are urgently needed to be finalized, and global organizations are actively competing to take the initiative. At that time, China’s ODCC (Open Data Center Committee) first introduced the 25G ToR switch specification and released details, which had become an important force in the rapid rise of 25G Ethernet.

As companies offer more and more different types of 25G SFP28 transceivers, DACs, and AOCs, the call for 25G Ethernet construction is getting higher and higher.

Year 2018 Till Now – Competition Against Other Network Products

2018 is a year of competition between 25G products and other products. During the year, sales of 10G products declined slightly. At the same time, 25G products received more and more recognition. In 2018, Supermicro opened path to 100G networking with new 25G Ethernet server and storage solutions. It offers a wide range of 25G NIC solutions that empower customers to future-proof nearly any Supermicro system by equipping it with 25G Ethernet networking technology. What’s more, Supermicro also offers a 25G switch (SBM-25G-100) with the X11 SuperBlade. This switch has twenty 25G downlink connections, four QSFP28 ports where each port can be configured as 40G or 100G uplink connections.

In any case, the arrival of 25G and its impact have given everyone confidence that data centers and suppliers can’t wait to plan for the era of 100G, 200G or even 400G.

How Far Can 25G Ethernet Go?

From all the above, you may have a general understanding of how 25G develops. At present, 25G is mainly used for switch-to-server applications. And it indeed gains ground in some aspects compared to 10G and 40G Ethernet. What’s more, you can see a clear trends of 25G market with a recent five-year forecast by industry analysts at the Dell’Oro Group below.

25G five year forecast

For a long run, it will go further since 25G switch offers a more convenient way to migrate to 100G or even 400G network.

Related Articles:

25G Switch Comparison: How to Choose the Suitable One?

Taking an In-depth Look at 25G SFP28

25G Switch Comparison: How to Choose the Suitable One?


25G Ethernet over a single lane has emerged as the new standard for sever-to-switch interconnections due to the undeniable rise in bandwidth requirements from private and public cloud data centers. Additionally, the popularity of the 25G switch, which has become the latest craze in recent years, has grown as data centers’ demands for faster speeds have increased. An easy look at the market for 25G Ethernet switches and a look at some of the most popular 25G switches will be discussed in this post.

What is a 25G Switch?

The new 25G technology that connects top-of-rack switches to servers has significant advantages in terms of density, cost, and power consumption. A single 25 Gb/s high-speed lane of the 25G Ethernet switch maximizes switch fabric utilization and bandwidth. The number of connected servers or uplinks per switch is maximized when there is only one channel per physical port. In the current 25G switch market, a typical 25G switch has 48 ports. Today, major switch manufacturers such as Cisco, Juniper, Mellanox, Dell, etc. have launched their 25G switches.

     ” Also Check- 25G switches

25G Switch Market Analysis

We know that before the introduction of the 25G technology, the available options consisted of one lane for 10G, four lanes for 40G, or four lanes at 25Gbps for 100G. The 25G technology is compatible with the existing module form factors, such as SFP28 and QSFP28, and it permits a breakout connection between 25G and 100G without altering the port that is located on the front of many 100G switches. In addition, many network switch manufacturers have announced their new 25G switches in the last three years to increase their market share due to their high speed and bandwidth.

  • Nexus 9300-FX platform switches from Cisco were made available for switching at 10G, 25G, and 100G;
  • For 25G, 50G, and 100G Ethernet networks, Mellanox introduced the SN2410 series of 25G Ethernet switches;
  • EMC networking S-series 25/40/50/100GbE was suggested by Dell to assist with data center migration;
  • Broadcom Introduced the BCM56960 Series of 25G Switches for Cloud-Scale Networking;
  • FS.com launched the N-Series spine/leaf 25G/100G switch for cost-effective data center solutions.

In the existing market, there are a wide variety of 25G SFP28 transceivers, DACs, and AOC cables, which can meet various network requirements. Dell’oro’s study said that Ethernet switch sales will keep going up until the end of the decade, with 25G and 100G ports seeing the most growth.

Notes: the source of the research: Crehan research.Inc

From the research we can see, at least in the next three years, 25G/50G/100G bandwidth will continue to grow and occupy half of the total network bandwidth, which in turn enhances the development of the 25G switch market. Though challenges still exist for 25G Ethernet, it’s not denied that the trend for ToR 25G switches cannot be blocked.

Why Do We Choose a 25G Switch?

Compared with 10G/40G switches, 25G Ethernet switches have significant advantages in many aspects. The following is mainly from three aspects: rate, power consumption, and technology maturity.

Rate: 25G can be easily upgraded to 50G and 100G. 100G was achieved prior to the development of 25G technology through applications and 10x10G technology. A single 25G LANE can transmit 50Gb/s of data if PAM4 level is used, and current 25G technology can achieve 100G.

Power consumption: The cost and consumption of a single Gbit are lower than those of 10G, and the power consumption of a 25G switch at full load is approximately 1.5 times higher than that of a 10G switch. Currently, as 25G technology continues to mature, costs are steadily and possibly gradually falling.

25G technology maturity: With the rapid development of AI and cloud computing, the demand for network bandwidth and latency is also rising. To provide more bandwidth, we must upgrade our 10G network to a 25G network. The real-world application of 25G data center switches in data centers demonstrates the maturity of 25G-related engineering technologies.

     ” Also Check- 25G Data Center Switches

Comparison Between Commonly Used 25G Switch in the Market

As previously stated, the 25G SFP28 switch market is booming as a result of the expanding bandwidth and speed as well as the promotion provided by switch manufacturers. Then, how can existing 25G Ethernet switches be used to optimize network performance while simultaneously controlling total investment? First, let’s compare the most frequently used 25G network switches.

25G Ethernet Switch Port Switch Capacity Packet Buffer Memory Max power consumption ONIE Support Price
SLX 9140
48*SFP28 Port
6* QSFP28 Port
1.8 Tbps 24 MB 489 W Yes $19,703.99
Cisco Nexus 93180YC-FX 48* SFP28 Port
6* QSFP28 Port
3.6 Tbps 40 MB 425 W No $11,681.99
Dell S5148F-ON 48* SFP28 Port
6* QSFP28 Port
3.6 Tbps 16 MB 516 W Yes No Infro
FS N8560-48BC 48* SFP28 Port
8* QSFP28 Port
4 Tbps 32 MB 300W No $6,899.00
Mellanox SN2410 48* SFP28 Port
8* QSFP28 Port
4 Tbps / / Yes $16,910.00

The features listed in the table for each 25G SFP28 switch are the same: 6 QSFP28 uplink ports and 48 SFP28 ports. These switches can also be used as ToR/Leaf switches. In most cases, switch-to-server applications make extensive use of 25G SFP28 switches.

If you don’t have a limited budget, the Cisco 25G switch might be a good choice for a 25G ToR switch because, despite its high price, it has excellent configuration and performance as well as a good reputation. Cisco switches are ideal for data centers due to all of these features. Naturally, Dell, Brocade, and Mellanox, as well as other manufacturers of 25G SFP28 switches, provide excellent alternatives for migrating networks from 10G to 50G and 100G.

However, purchasing a 25G switch like the FS N8560-48BC, which is compatible with SDN (Software Defined Networks) via OpenFlow 1.3.11, is a better option for those who don’t care about brand. It is also compatible with the advanced hardware-based VXLAN feature, which enables it to support over 16 million virtual networks, making it a good choice for data center solutions that are affordable.

” Also Check- How to Use 25G Switch for Switch-to-Server Connection


Switching to a 100G network with a 25G switch is easier because it reduces the number of cables and switches that are required in network designs, resulting in lower CAPEX and OPEX. Are you prepared to deal with the rapidly evolving 25G switch market?