SFP28 Archives - Fiber Optical Networking

What Is 25G CWDM SFP28?

CWDM SFP28 transceiver operates on four wavelengths (1270, 1290, 1310, and 1330 nm), which combine to be suitable for 100G in data center networks through course wavelength division multiplexing (CWDM). It is an enhanced version of SFP+ designed for 25G signal transmission. The maximum reach is 10 kilometers. The physical structure of the SFP28 is the same as the popular SFP module and SFP+ module, but the electrical interface is upgraded to 25Gbps per channel. The optical connection of CWDM SFP28 is duplex LC fiber patch cables, and the CWDM SFP28 shall be backward compatible with the traditional 10G SFP + pluggable. 25G CWDM SFP28 is a dual directional device with a transmitter, a receiver and a control management interface (2-wire interface) in the same physical package. The 2-wire interface is used for serial ID, digital diagnostics and module control functions. This module provides very high functionality and integration and is accessible via a two-wire serial interface.

What Is the Difference Between CWDM SFP28 and CWDM SFP+?

We know that SFP+ is made to operate at 10Gb/s. SFP28 uses the same common form factor as SFP+, but the electrical interface is upgraded to 25Gbps per channel. CWDM SFP+ transceiver often operates at a nominal wavelength of CWDM wavelength. To be specific, CWDM SFP+ transceiver can support 18 wavelengths from 1270nm to 1610nm, and its transmission distance is from 20km to 80km. While CWDM SFP28 has four main wavelengths of 1270nm, 1290nm, 1310nm, and 1330nm. And its maximum transmission distance is 10km. Compared to SFP+ solutions, SFP28 has higher bandwidth, superior impedance control, and less crosstalk. A report once said the price of per unit of 10G bandwidth for 25G server Ethernet adapters is much lower. 25G SFP28 provides 2.5 times the bandwidth, but the price is not 2.5 times. All in all, the main advantages of SFP28 over SFP+ can be summarized into two points: lower cost and higher bandwidth.

Advantages of Using 25G CWDM SFP28

Compared to 4G, the spectrum bandwidth used by 5G has increased rapidly. 4G uses a maximum spectrum bandwidth of 20MHz, while 5G low-frequency band uses 100MHz bandwidth, and 5G high-frequency band (millimeter wave) uses 800MHz bandwidth with an upper limit of 1GHz. At present, there is still some difficulty in data processing and transmission of 5G high-frequency band (millimeter wave) and large bandwidth. Considering the smooth evolution of 5G equipment and the development of the industry chain, 25G CWDM SFP28 solution can well solve the current 5G millimeter wave pre-transmission problem. In this case, one 100G QSFP28 optical module is used on the antenna side and four 25G CWDM SFP28 optical modules are used on the baseband side. The construction of a 5G millimeter wave pre-transmission bearer network can be completed with only one MUX/DeMUX bridge connection. There is no need for devices to add an additional shunt function to perform rate matching on both ends. In all, 25G CWDM SFP28 can cost-effectively upgrade network bandwidth to support next-generation 50G (2x25G ), 100G (4X25G) and storage solutions for cloud and web-scale data center environments.

Conclusion

SFP28 assembly solution supports a new generation of high-density 25G Ethernet switches that facilitate server connectivity in data centers and provide a cost-effective upgrade path for enterprises deploying 10G Ethernet links in the future. If you are considering to build a 25 Gigabit Ethernet network, you can visit FS.COM, which offers a variety of CWDM SFP28 with famous compatible brands.

In recent years, the fast growth of data centers leads to increase in global data traffic, which give rise to the need for faster data transmission over a network. 25G Ethernet is the product of that condition. 25G Ethernet is regarded as an incremental update from 10G Ethernet, and it supports 100G Ethernet with single lane at 25Gbps. Due to the booming of 25G, some industry experts claimed that 40G Ethernet is dead, which is biased in some degree. Then 25G vs. 40G Ethernet, which is even better?

Advantages and Disadvantages of 25G and 40G Ethernet

Advantages of 25G Ethernet

Different from 40G and 100G, 25G is a single-lane variant for 25Gbps operation, and that allows a breakout of 100G, which fit the most popular form factors. Based on existing module form factors, such as SFP28 and QSFP28, 25G operations allow for a breakout connection that is configurable as either 25G per lane or the full 100G without changing the port on front of switches, bring more flexibility in the rack and front-panel connections. In addition, with the 25G Ethernet, network operators are no longer forced to use a 40G QSFP port to go from one individual device to another to achieve 100G throughput. The final advantage of 25G is that it can use existing optical plants (depending on what was installed) and increase the bandwidth by 2.5x without changing the physical infrastructure.

25g ethernet sfp28

Disadvantages of 25G Ethernet

As 25G Ethernet is just rising, the interoperability becomes an important factor to ensure wide market adoption and to offer higher speeds for future applications. Besides, compared with 10G 40G and 100G, there aren’t many products of 25G, which limit the development of 25G networks.

Advantages of 40G Ethernet

40G Ethernet is an Ethernet standard developed by the IEEE 802.3ba Task Force to support sending Ethernet frames at 40 gigabits per second. It also addresses physical layer specifications for communication across back planes, copper cabling, multimode fiber optic cable, and single mode fiber. And 40G Ethernet technology is more mature compared with 25G. In the market, there are various types of products for 40G applications, especially the MPO trunk cable assemblies, cassettes, and QSFP 40G optical modules, which offers the required bandwidth for different applications.

40G solution

Disadvantages of 40G Ethernet

At present, 40G is popular in data centers and no drawbacks found. If we have to say one, the utilization of fibers may be one. As we all know, 12-fiber cabling solution is common in 40G networks. But there are four fibers unused, resulting in fiber waste.

Comparison Between 25G and 40G Ethernet in Network

Application

At present, 25G is mainly used for switch-to-server applications. While 40G is for switch-to-switch applications. In other words, no one is using 25G for switch-to-switch links right now. Even the industry giant like Cisco doesn’t offer 25G optical transceiver. But with the fast development of 25G Ethernet, 25G for switch-to-switch application maybe come into reality in the near future.

Switches Selection

Switches are important when comparing 25G and 40G Ethernet. Most switches are currently sold, like Cisco 93180YC-EX, Arista 7060CX-32S support both 10G and 25G, and the price is not higher than older 10G products with full backward compatibility. For example, each SFP28 port supports 1G, 10G or 25G, and each QSFP28 port supports 10G, 25G, 40G, 50G or 100G.

Cabling Options

Cabling options determine how far the two types of Ethernet go. It’s a big mistake to ignore cabling. In the market, there are several types of cabling options, and there are some big swings in price. Here is a simple comparison.

25g ethernet vs 40g ethernet

Summary

From the comparison above, we can draw a conclusion that 25G Ethernet can be used for data centers, but it doesn’t mean 40G is dead. Even though 25G Ethernet seems to have a brilliant future, under present conditions, 40G is a safe choice due to its mature market adoption. Perhaps in a few years, 25G connectivity will be a cheaper alternative.

Taking an In-depth Look at 25G SFP28

How Far Can 25G Ethernet Go?

25G SFP28 Cable: The Most Economical Option for ToR Server Connection

The Changing Network Architecture in 25G/100G Data Center

Tag: SFP28

The Arrival of 25G CWDM SFP28

What Is 25G CWDM SFP28?

What Is the Difference Between CWDM SFP28 and CWDM SFP+?

Advantages of Using 25G CWDM SFP28

Conclusion

25G Vs. 40G Ethernet: Who Is the Winner?