SFP28 vs SFP+ Transceiver, What is the Difference?

Initial Published: April 18, 2019

With the introduction of new technologies and economic drivers, many companies’ data center landscapes are moving toward higher speeds, scalability, and performance levels. As we all know, a broader technology shift requires more networks and bandwidth. Therefore, more organizations are upgrading from 10GbE to 25GbE technology. The SFP+ and SFP28 are the most popular correlated form factor.

This article will focus on the difference between the SFP+ transceiver and the SFP28 transceiver. By exploring the crucial differences and core features, you will learn how to choose and identify them.

Keep reading to learn more about SFP28 vs SFP+. 

Table of Contents

• 10GbE Basics
• What is SFP+
• What is SFP28
• SFP28 vs SFP+, What is the difference?
• FAQ
• Conclusion

10GbE Basics

10 Gigabit Ethernet (10 GbE, 10 GE, or 10 GigE) is a disruptive telecommunications technology that transmits packets over Ethernet at a rate of 10 billion bits per second. This innovation extends the reach of traditional and familiar Ethernet in local area networks (LANs) to a broader range of network applications, including high-speed storage area networks (SANs), wide area networks (WANs), and metropolitan area networks (MANs).

10G Ethernet provides a more efficient and cheaper way to move data over network backbone connections. The IEEE 802.3ae standard allows up to 100 kilometers between physical locations on a single mode fiber. Both single-mode and multimode fiber systems can be used for 10 GbE applications.

The 10 GbE standard is fully interoperable with existing Ethernet protocols. It differs from traditional Ethernet in that it is a full-duplex protocol, which does not require the Carrier Sense Multiple Access/Collision Detection (CSMA/CD) protocols.

In other respects, 10 GbE is identical to the original Ethernet protocol. That is important for network administrators since 10G Ethernet can be easily deployed in existing networks when speed requirements increase. It still provides cost-effective technology that supports high-speed, low-latency needs.

What is SFP+?

SFP+ is an enhanced SFP with higher speed. Its typical rate is 10Gbps, but it has extended variants like 8G and 16G. The SFP+ also shares the same appearance and size as the traditional SFP. Its specifications were defined in the SFF-8431 standards. 

When discussing this term, the most common words are SFP+ module and SFP+ port. For more detailed information, please read our other post.

Generally speaking, The SFP+ module includes SFP+ transceivers, SFP+ DAC, and SFP+ AOC.

Take the SFP+ transceiver as an example. It typically supports 10G Ethernet and SDH/SONET STM64 in most applications. Meanwhile, the Fibre channel SFP+ supports 8G or 16G data rates in the SAN application. 

It is smaller than the earlier 10G XENPAK, 10G X2, and XFP modules. Therefore, it provides nearly double port density and has become the market’s most popular 10G transceiver. 

What is SFP28?

The SFP28 form factor is similar in size and appearance to the SFP+ form factor but supports a much higher speed of 28Gbps, hence the name “SFP28”. 

Simply put, SFP28 is an enhanced version of SFP+ designed for 25G or 28G connectivity. It has the same form factor and appearance as the SFP+ but supports up to 28Gbps electrical interfaces per channel.

The SFP28 products are usually classified as SFP28 modules and SFP28 ports. Generally, the SFP28 module includes an SFP28 transceiver, SFP28 DAC, and SFP28 AOC cable. 

Unlike the SFP28 module, the SFP28 port is typically assembled in the networking switch and BBU device in the wireless station to accept the suitable transceiver.

Key benefits of 25G SFP28 Transceiver

• Run business applications and services faster with 5x throughput, with similar economic benefits to 10GbE
• Future-proof infrastructure, backward compatible with 10G, easier to migrate to 100G
• Economic advantages of cost and revenue generation using an open network architecture
• It runs on cables like 10G, so switching to 25G does not require any cabling infrastructure upgrades – it is fully compatible with the existing 10G cabling infrastructure.
• Reduce capital and operating expenses: Deploying SFP28 to build 25G networks enables organizations to significantly reduce the number of switches and cables required and the cost of space, power, and cooling facilities compared to 10G and 40G technologies.

SFP28 vs SFP+, What is the difference?

Before we compare SFP28 and SFP+, let us see the table below.

Form	Standard	Datarate	Wavelength	Media	Distance	Connector	DOM	Size	Power Consumption	Application	Price
SFP+	SFP+ MSA	8G 10G 16G	850nm 1310nm 1550nm CWDM DWDM BiDi Copper	OM3 OM4 SMF Twinax	120km	LC RJ-45	Yes	Similar to SFP	Lower	Ethernet Fiber Channel CPRI Datacenter	$$
SFP28	IEEE 802.3by SFP28 MSA	25G 32G	850nm 1310nm CWDM DWDM BiDi Copper	OM3 OM4 SMF Twinax	40km	LC	Yes	Similar to SFP	Higher	Datacenter Cloud computing	$$$

This table shows that both have the same appearance and are mating compatible. Both modules also share standards similar to SFF-8432 and SFF-8472.

The differences between SFP28 and SFP+ are mainly in the below list:

• First, the most distinguished difference is speed. SFP+ typically supports 10G and 8G/16G fiber channels. However, SFP28 generally is for 25G speed links and sometimes has an extended data rate of 28G or 32G.
• Second, SFP28 stands out in terms of its superior performance. It provides increased bandwidth, superior impedance control, and less crosstalk than the SFP+ solution, instilling confidence in its high-speed network capabilities.
• Third, although SFP28 costs more than SFP+, it provides a better cost advantage for high-speed networks. For example, to build a 100G link, you may choose 10x10G SFP+ SR or 4x25G SFP28 SR. Using the OPTCORE 25G solution, the customer may save around 13%.

Frequently Asked Question

Q: Can I use SFP28 transceivers in SFP+ ports?

A: The answer is yes, because SFP28 is backward compatible with SFP+ ports and can be fully functional. However, you should ensure the SFP28 transceiver supports a dual rate of 10G/25G, which says it is 10G/25GbE SFP28.

Q: Can I use SFP+ Transceivers in SFP28 ports?

A: No, you can not use the SFP+ transceiver in the SFP28 port. The SFP28 port supports a 25G or 32GFC data rate, whereas the SFP+ transceiver typically supports a 10G data rate. 

However, if the switch allows the port data rate to be set to 10Gbps, you may use the SFP+ in the SFP28 port. In this case, the SFP28 port acts as a 10G SFP+ port.

Q: Do you have any dual rate 10G/25G transceiver?

A: Yes, we have. Our dual-rate 10G/25G SFP28 transceiver supports both rates, allowing you to use them flexibly in an SFP+ or SFP28 port. The model includes 10G/25GBASE-SR, ESR, and LR.

Q: Does SFP28 support 1G?

A: No, SFP28 does not support 1G. Although the SFP28 fits in the SFP port, it can not work in the 1G SFP port.

Conclusion

Many data centers will migrate from 10GbE to 25GbE or 40GbE in the following years. A 25G Ethernet Switch and SFP28 transceiver are critical for a smooth migration. Since the 25G SFP28 ports also support 10G speed, most IT organizations will easily decide on existing fiber cabling upgrades.

As an innovative optical transceiver supplier, Optcore offers a broad portfolio of SFP+, SFP28, DAC, AOC, and fiber optic cables to meet all the 25G connection applications.

Read more:

• 40G QSFP+ vs. 100G QSFP28 Transceiver: Pros and Cons
• The Big Differences Between SFP, SFP+, SFP28, QSFP+, QSFP28, QSFP-DD, and OSFP
• What is SFP+ Transceiver?
• What is SFP module?