CFP8 VS QSFP-DD: Which 400G Transceiver to Choose?

With the large-scale deployment of 100G, the ultra 100G technology — 400G has gradually become a hot topic in the industry. There is no doubt that 400G will eventually be the next major Ethernet speed in the data centers. In fact, the world’s leading optical transceiver manufacturers have launched their own 400G optical transceiver modules such as 400G QSFP-DD, OSFP, CFP8 and COBO transceivers for 400G data transmission. This article will focus on the 400G CFP8 VS QSFP-DD transceivers.

What Is 400G QSFP-DD Transceiver?

QSFP-DD refers to Quad Small Form-factor Pluggable Double Density. It is a new 400G transceiver designed with eight lanes that operate up to 25Gb/s NRZ modulation or 50Gb/s PAM4 modulation, providing solutions up to 200Gb/s or 400Gb/s aggregate. The term “Double-Density” refers to the doubling of the number of high-speed electrical interfaces that the module supports compared to the regular QSFP28 module. 400G QSFP-DD transceiver enables up to 14.4Tb/s aggregate bandwidth in a single switch slot. By quadrupling aggregate network switch bandwidth while maintaining port density, QSFP-DD can support continuing growth in network bandwidth demand and data center traffic.

alt CFP8 VS QSFP-DD 400G-QSFP-DD-Transceiver

What Is 400G CFP8 Transceiver?

CFP8 transceiver is the 400G form factor type specified by the CFP MSA (Multi-Source Agreements). It is the same size as the CFP2 transceiver but uses a new 16x25G electrical I/O connector. As for bandwidth density, it respectively supports eight times and four times the bandwidth density of CFP and CFP2 transceiver. Generally speaking, there are four types of CFP8 modules on the market— CFP8 FR8/LR8, CFP SR16, and CFP DR4. The interfaces of the four CFP8 transceivers are generally specified to allow for 8 x 50Gb/s, 16 x 25Gb/s, 4x100Gb/s modes, respectively.

alt400G-CFP8-Transceiver

CFP8 VS QSFP-DD: Which 400G Transceiver to Choose?

The upgrading path of the CFP series is CFP-CFP2-CFP4-CFP8, and QSFP-DD has also experienced hardware specifications from 1.0 to 4.0. These are all long-established form-factor series. Compared to the QSFP series, the CFP series seems to be less popular for obvious reasons — large size and high power consumption. Below we will detail the differences between CFP8 VS QSFP-DD.

CFP8 VS QSFP-DD: Form Factor

In general, the width, length, and thickness of QSFP-DD are 18.35mm, 89.4mm and 8.5mm, while those of CFP8 are 41.5mm, 107.5mm and 9.5mm. The size of CFP8 transceiver is larger than QSFP-DD, and the volume is more than three times that of QSFP-DD. However, since the CFP8 transceivers are applied for telecommunication applications, and the port density requirements are not as high as in the data center, so the size is acceptable.

CFP8 VS QSFP-DD: Bandwidth

The maximum bandwidth of CFP8 and QSFP-DD is 400Gb/s, but CFP8 only supports 400Gb/s (16x25G, 8x50G, 4x100G), while QSFP-DD supports both 200Gb/s (8x25G) and 400Gb/s (8x50G). Thus, QSFP-DD works better than CFP8 in the performance.

CFP8 VS QSFP-DD: Thermal Capacity and Power Consumption

QSFP-DD has a thermal capacity of 7 to 12 watts, while CFP8 allows up 24 watts power consumption. The larger the thermal capacity, the greater the power consumption that the optical transceiver can withstand. With the advancement of technology, some industry-leading manufacturers have been able to reduce the power consumption of optical modules far below the upper limit of thermal capacity specified by MSA, so the larger thermal capacity does not seem to be a real advantage. However, as we all know, the lower the power consumption, the better.

CFP8 VS QSFP-DD: Backwards Compatibility

There is not any mention of backward compatibility in the hardware specification of CFP8. In fact, the entire CFP series transceiver does not seem to be backward compatible. However, 400G QSFP-DD transceiver has the advantage of backward compatible with QSFP, QSFP+, and QSFP28, which provides flexibility for end users and system designers.

Conclusion

After introducing and comparing QSFP-DD and CFP8, we find that QSFP-DD has unparalleled advantages in 400G applications. It is expected that when the world’s leading hyper-scale data centers begin to deploy 400G, QSFP-DD will become the mainstream form-factor of 400G optical transceivers. It is undeniable that QSFP-DD transceiver is the best choice for your network.

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The Arrival of 25G CWDM SFP28

With the ever-increasing demands for faster speed and higher density, SFP transceiver modules have undergone several generations of upgrade for signal speed capability and port density updates, from the original SFP to SFP+ and then to the new SFP28 type. 10GbE has encountered bottlenecks due to the surge in demand for high bandwidth. 25G Ethernet becomes the new standard that provides significant density, cost, and power advantages for server switching links. Today we will come to know the CWDM SFP28 with 25G Gigabit Ethernet.

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.

altThe Arrival of 25G CWDM SFP28

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.

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What’s the Difference: Transceiver vs Transmitter

Today, let’s learn and compare two terms in optic communication: transceiver vs transmitter(originated in the early 1920s. Looking up in the dictionary, we can distinguish that transmitter is a device that transmits something(in all senses), and transceiver is a combined transmitter and receiver.

Transmitter

A transmitter can either be a separate piece of electronic equipment or an integrated circuit (IC) within another electronic device. A transmitter generates a radio frequency current applied to the antenna, which in turn radiates radio waves for communication, radar and navigational purposes. The information that is provided to the transmitter is in the form of an electronic signal. This includes audio from a microphone, video from a TV camera, or a digital signal for wireless networking devices. The electronics for a transmitter are simple. They convert an incoming pulse (voltage) into a precise current pulse to drive the source. Different transmitter has different functions. Take the optical transmitter as an example, it consists of the following components: optical source, electrical pulse generator and optical modulator. And the role of it is to convert the electrical signal into optical form, and launch the resulting optical signal into the optical fiber.

Transceiver

A transceiver is a device made up of both a receiver and transmitter (the name “transceiver” is actually short for transmitter-receiver) and these two gadgets are in a single module. When no circuitry is common between transmit and receive functions, the device is a transmitter-receiver.

Transceivers can be found in radio technology, telephony as well as Ethernet in which transceivers are called Medium Attachment Units (MAUs) in IEEE 802.3 documents and were widely used in 10BASE2 and 10BASE5 Ethernet networks. Fiber-optic gigabit, 10 Gigabit Ethernet, 40 Gigabit Ethernet, and 100 Gigabit Ethernet utilize transceivers known as GBIC, SFP, SFP+, QSFP, XFP, XAUI, CXP, and CFP, among which Cisco SFP is the most popular one. In addition, 1000BASE-T SFP, 10GBASE-T SFP+ and 1000BASE-T copper SFP we mentioned before are all transceivers.

third-party-transceiver

Transceiver vs Transmitter

From the above information, we can know that the transmitter can only be used to transmit signals, while the transceiver can both transmit and receive signals. However, many view transceivers as a compromise in terms of performance, functionality, portability and flexibility and if they had any practical value it would be in mobile and portable applications. Transceivers sacrificed some features and performance to gain the smaller size/weight and cost.

As for the portability, a transceiver just needs the space of one module, but functions as two different modules. It is easy to be taken on the go. Separate transmitter is not as convenient in some circumstances as it is probably heavier, and takes up more room. But they are advantageous because each could benefit from its own design, without compromising in areas such as I-F frequency choice, conversion frequencies, and audio stages and they are easier to build and work on.

As far as the price is concerned, in most cases, a separate transmitter consumes more power. And the price of a single transceiver is much lower than that of a transmitter plus a receiver.Using a common frequency generation/tuning scheme, power supply and other components, it costs less to manufacture a transceiver than a separate transmitter and receiver.As to how to choose from them, the answer depends on your application.

Conclusion

You may find many transmitters in you life, like the TV remote control. Although transceiver is not commonly noticed around you, it is actually commonly applied to many places. We can say that it is invisible but versatile. I sincerely hope that this article will help you understand the difference: transceiver vs transmitter, only then, can you use them in the right way.

MGBSX1 vs MGBLH1: What’s the Difference?

Cisco SFP is fiber optic transceiver modules that provide fast and reliable connectivity between switches that are located in separate buildings, or on a large campus network. Its long-standing charm and good reputation have intrigued many people for a long time, inducing us to lift the veil on it. Today’s article will generally introduce the Cisco 1000BASE SFP transceivers: MGBSX1 vs MGBLH1.

MGBSX1 :1000BASE-SX SFP transceiver

MGBSX1 is a hot pluggable 1000BASE transceiver invented by Cisco. The 1000BASE-SX standard optics are developed to support lower cost multi-mode fiber runs in horizontal and shorter-length backbone applications. The MGBSX1 transceiver offers the ability to tap into faster networking speeds using fiber optic cabling. It supports dual data-rate of around 1 Gbps, with its operating temperature ranging from 32º to 158ºF (namely, 0º to 70ºC). The industry-standard Cisco Small Form-factor Pluggable Gigabit Interface Converter is a hot-swappable input/output device that plugs into a Gigabit Ethernet port or slot, linking the port with the network. The NGBSX1 SFP is compatible with the IEEE 802.3z 1000BASE-SX standard and operates on 50 micrometer multimode fiber links up to 550m and on 62.5 micrometer FDDI-grade multimode fibers up to 220m. More importantly, installing this module is as easy as sliding it into an accompanying port on a compatible Cisco switch.

MGBSX1

MGBLH1 :1000BASE-LH SFP transceiver

MGBLH1 is also a 1000BASE SFP transceiver. However, it differs from MGBSX1 in that LH stands for long haul. Many vendors use LH for certain SFP modules, this SFP type is similar with the other SFPs in basic working principle and size. However, LH isn’t a Gigabit Ethernet standard, yet is compatible with 1000BASE-LX standard. The MGBLH1 transceiver module provides a low cost high-performance connection. Compliant with specifications of SFP transceiver MSA specification, 1000BASE-LH SFP operates a distance up to 70km over single-mode fiber. Cisco MGBLH1 1000BASE-LH SFP covers a link length of 40km that make itself perfect for long-reach application. Morever, The MGBLH1 transceiver provided by FS.COM is individually tested on a full range of Cisco Linksys equipment and passes the monitoring of FS.COM intelligent quality control system.

MGBLH1

MGBSX1 vs MGBLH1

Model MGBSX1 MGBLH1
Media Type Multimode Fiber Single Mode Fiber
Max Range 500 m 40 km
Wavelength 850 nm 1310 nm
Connector LC LC

The large diameter core of multimode fiber increases the light reflection created as light travelling. Because of the high dispersion and attenuation rate with the multimode fiber, the quality of the signal is reduced over long distances. Therefore, the MGBSX1 is typically used for short distance, data and audio/video applications in LANs. Oppositely, MGBLH1 can be applied to long distance transmission. However, the actual distance will vary based on fiber plant and operating environment.

Conclusion

MGBSX1 vs MGBLH1: have you known the differences? Although they share something in common, they are totally different 1000BASE SFP transceivers. If the working distance is clear, you can choose from the two SFP transceivers according to my advice. When considering other elements, you can turn to the experts on FS.COM. There is a team of experienced networking specialists that is ready to assist you. Choose FS and save money!

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Are You Ready For 400G Ethernet?

The rapid development in telecom industry is driving massive demand for higher bandwidth and faster data rate, from 10G to 40G and 100G, will this keep going on? The answer is definitely “Yes”. Some time ago, migration from 10G to 40G or 25G to 100G has been a hot spot among data center managers. While recently, 400G solutions and 400G components are coming. Are you ready for 400G? This article will share some information about 400G Ethernet.

Overview of 400G

In the past couple of years, modules with four 25/28G lanes or wavelengths are the solutions for 100G Ethernet. However, they were expensive at the beginning. Until 2016, the optical components industry has responded to the demands with 100G solutions that already cost less per gigabit than equivalent 10G and 40G solutions, and new developments to further drive down cost and increase bandwidths. The next generation is 400G Ethernet. The IEEE has agreed on PSM4 with four parallel fibers for the 500 meters 400GBASE-DR4 specification that is part of the IEEE802.3bs standard being developed for approval by the end of 2017. The industry is already developing optical components for 400G Ethernet solutions. The following figure shows telecom and datacom adoption timelines.

Telecom and datacom adoption timelines

We can visually see that telecom/enterprise applications first adopted 100G technology in the form of CFP modules. Data centers generally did not adopt 100G interfaces until the technology matured and evolved towards denser, lower power interfaces, particularly in the form of QSFP28 modules. However, as the hyperscale data center market scales to keep pace with machine-to-machine communications needs, data center operators have become the first to demand transmission modules for data rates of 400G and beyond. Therefore, the 400G era is now upon us.

Modules for 400G

We know that the QSFP28 modules for 100G Ethernet and SFP28 modules for 25G Ethernet are now the dominant form factors. Though CFP, CFP2 and CFP4 modules remain important for some applications, they have been eclipsed by QSFP28 modules. To support higher bandwidth, what is the right module for 400G? The first CFP8 modules are already available. QSFP-DD is backward compatible with QSFP, and OSFP may deliver better performance, especially as networks move to 800G interfaces.

CFP8 module: CFP8 module is the newest form factor under development by members of the CFP multisource agreement (MSA). It is approximately the size of CFP2 module. As for bandwidth density, it respectively supports eight times and four times the bandwidth density of CFP and CFP2 module. The interface of CFP8 module has been generally specified to allow for 16 x 25 Gb/s and 8 x 50 Gb/s mode.

100G CFP to 400G CFP8

QSFP-DD module: QSFP-DD refers to Quad Small Form Factor Pluggable Double Density. It uses eight 25G lanes via NRZ modulation or eight 50G lanes via PAM4 modulation, which can support optical link of 200 Gbps or 400 Gbps aggregate. In addition, QSFP-DD module can enable up to 14.4 Tbps aggregate bandwidth in a single switch slot. As it is backwards compatible with QSFP modules, QSFP-DD provides flexibility for end users and system designers.

QSFP-DD vs QSFP

OSFP module: OSFP (Octal Small Form Factor Pluggable) with eight high speed electrical lanes is able to support 400G (8x50G). It is slightly wider and deeper than the QSFP but it still supports 36 OSFP ports per 1U front panel, enabling 14.4 Tbps per 1U. The OSFP is able to meet the projected thermal requirements for 800 Gbps optics when those systems and optics become available in the future.

OSFP module

Conclusion

Judging from the current trends, 400G will become the mainstream in the near future. But there are still some challenges for it to overcome, such as high capacity density, low power consumption, ever lower cost per bit, and reliable large-scale manufacturing capabilities. You never know what surprise the network will bring to you, let’s wait and see the 400G’s time.