2018-02-10

100G QSFP28 Optical Transceivers: A Cost-effective Solution

The continuous and rapid development of the Internet as well as the desire of people for higher speed optical networks facilitated the vigorous development of the entire optical communications industry and strongly promoted the independent R & D and innovation in many core technologies including optoelectronic devices technologies. 100g optical transceiver is regarded as the product of this big data era.

The first generation of 100G optical modules is CFP optical module with very large volume, then CFP2 and CFP4 optical modules appears. CFP4 optical module is the latest generation of 100G optical module, the width is only 1/4 of CFP optical module. Its package size is not same as the QSFP + optical module. The QSFP28 optical module has a smaller package size than the CFP4 optical module, which means the QSFP28 optical module has a higher port density on the switch. The following are several 100G QSFP28 series optical modules:

Main Types of QSFP28 Optical Transceivers


100G QSFP28 LR4 is a 100Gb/s transceiver module designed for optical communication applications compliant to 100GBASE-LR4 of the IEEE P802.3ba standard. 



100G QSFP28 SR4 is a four-channel, pluggable, parallel, fiber-optic QSFP+ SR4 optical transceiver module for 100/40 Gigabit Ethernet, Infiniband DDR/EDR and 32GFC applications.



100G QSFP28 PSM4 is a four-channel, pluggable, parallel, fiber-optic QSFP28 PSM4 optical transceiver module for 100/40 Gigabit Ethernet and Infiniband DDR/EDR Applications.



100G QSFP28 CWDM4 is a 100Gb/s transceiver module which is designed for optical communication applications compliant with the QSFP MSA, CWDM4 MSA and portions of IEEE P802.3bm standard.



Of course, QSFP28 series also includes 100G QSFP28 AOC; these products have played an important role in the development of 100G.

Advantages of 100G QSFP28 Optical Transceivers


1. Power Consumption


The power consumption of QSFP28 typically is no more than 3.5W, while the power consumption of other 100G optical modules typically is between 6W and 24W. From this, the power consumption of QSFP28 optical modules is much lower power than other 100G optical modules.

2. Cost


Now the data center is mainly 10G network architecture, in which the interconnection solutions are mainly 10GBASE-SR optical module and duplex LC multimode fiber jumper. If the existing 10G network architecture based on the direct is upgraded to 40 / 100G network, it will save a lot of time and cost. Therefore, one of the major interconnection trends in data centers is to upgrade from 10G networks to 40 / 100G networks without changing existing duplex multimode infrastructure. In this case, the MPO / MTP branchable cable is undoubtedly the ideal solution for a 10G upgrade to 40 / 100G.

3. Bandwidth


The QSFP28 uses the advanced 100G transport technology to provide the data center with a connection between the chassis switch and the core network, providing up to 150% greater panel bandwidth density than the 40G QSFP solution.

Optical Module Test


When using optical modules, test performance is an essential step. Optical module is composed of transmitter and receiver, so when we test, it is generally divided into four steps, which mainly includes the transmitter and receiver test.

First, the transmitter part:


When testing, pay attention to the wavelength and shape of the transmitter output waveform, as well as the receiver's jitter tolerance and bandwidth. When testing the transmitter, note the following:

1. The quality of the input signal used to test the transmitter must be good enough. In addition, the quality of the electrical measurements must also be confirmed by jitter and eye measurements. Eye diagram measurements are a common way to check the transmitter's output waveform because the eye diagram contains a wealth of information that reflects the overall performance of the transmitter.

2.The output optical signal of the transmitter must be measured by the optical quality index such as eye pattern test, optical modulation amplitude and extinction ratio.

Second, the receiver part:


Unlike test transmitters, the quality of the optical signal must be sufficiently poor when testing the receiver that a light pressure eye pattern representing the worst signal must be created. This worst case optical signal must pass through jitter measurements and light Power test to calibrate.

1. Eye pattern test, this will ensure that the eye "eye" is open. Eye diagram testing is usually done at the depth of the bit error rate;

2. Jitter test to test different types of jitter;

3. Jitter Tracking and Tolerance, testing the internal clock recovery circuit to track the jitter.


All in all, testing light modules is a complex undertaking, but it is also an indispensable step in ensuring good performance. Eye diagram measurement is a widely used measurement method that can effectively test the transmitter of an optical module. The optical module receiver test is more complex, but also requires more testing methods. 

2018-02-04

Analysis of 100G Optical Transceivers from Another Point of View

With the development of science and technology, the application of optical communications products in real life is becoming more and more widespread. The demand for network technology is also getting higher and higher. Therefore, 100G optical transceivers are gradually appearing on the market. The development of 5G and Data Center further make the 100G optical transceivers become the mainstream of the optical transceiver market gradually. Perhaps you have had a certain understanding of 100G optical transceivers, but if we analysis 100G optical transceivers from another point of view, you will find something different.

Development Background of 100G Optical Transceivers


For the earliest developed 100G optical transceiver, the form factor is CFP, developed in 2010. At that time, IEEE launched 100G optical transceiver SR10, LR4 and ER4 three standards, separately aiming at the 100m, 10Km and 40Km transmission. Followed by that, the IEEE standard added the new 100G SR4 project, but in 2013 did not reach consensus and vacancies. By 2016, the 100G optical transceivers used by various data centers were mostly the 25Gbps Serdes program, and the 100G optical transceivers that use the 50Gbps Serdes planned slowly appeared.

The Facing Problems for 100G Optical Transceivers


1. Channel Distance: The DWDM system supporting the 50GHz wavelength distance is very extensive. The 100G optical transceiver needs to meet the condition of supporting the 50GHz wavelength distance, therefore, the pattern of high spectral power should be used.

2. OSNR (optical signal-to-noise ratio): Under the same pattern, 100G optical transceivers requires10dB higher than 10G optical transceivers and 4dB higher than 40G optical transceivers. Therefore, a low OSNR tolerance code and high coding gain FEC algorithm are needed.

3. CD Margin: Under the same conditions, 100G optical transceiver dispersion tolerance only needs 1/100 of 10G optical transceiver, accounting for 16/100 of 40G optical transceiver. Therefore, 100G optical transceivers can use dispersion compensation technology, in the electric field or the optical domain compensation to complete the dispersion compensation for each wavelength.

4. PMD Tolerance: Under the same conditions, PMD (polarization mode dispersion) tolerance of 100G optical transceiver is 1/10 of 10G optical transceivers, accounting for 4/10 of 40G optical transceiver, so you need to choose coherent reception plus digital signal processing.

5. Nonlinear Effects: Compared with 10G / 40G optical transceiver, the nonlinear effects of 100G optical transceivers are messier.



The Types and Advantages of 100G Optical Transceivers


The main form factors of 100G optical transceiver include: CFP, CFP2, CFP4 and QSFP28. To compare their advantages, the main factor to consider is the costs and power consumption for Data Centers.

1. CFP optical transceiver supports all C-band wavelengths tunable and can complete the link detection, which use a common optical dual-binary modulation format ODB, convenient layout, power consumption is less than 24W.

2. The volume of CFP2 optical transceiver is one-half of CFP, its integration is 2 times CFP. It can complete the wide dynamic input range based on SOA to achieve stable admission sensitivity, support a full CFP optical transceiver, its low power consumption is lower than 9W.

3. The volume of CFP4 optical transceiver is one-half of CFP2, its integration is twice that of CFP2, front panel port density is also doubled compared with CFP2. CFP4 optical transceiver follows the MSA protocol, support the same rate as CFP/CFP2. Its transmission power increases significantly, but the power consumption drops significantly, only about half of the original, the system cost is lower than the CFP2. In addition, CFP4 optical transceiver uses 4 * 25 forms, through the 4 * 25G channel, complete 100G transmission. The transmission power is higher with higher stability.

4. The form factor of QSFP28 optical transceiver is smaller than the CFP4 optical transceiver. QSFP28 optical transceiver power consumption is generally not more than 3.5W, the use of QSFP28 optical transceiver can directly upgrade from 25G to 100G not through 40G, and therefore the cost is lower.


Types
Standard
The Largest Transmission Distance
Connector
Channel
Wavelength
Fiber Types
CXP
SR10
100m
MPO24
12*10G
850nm
MMF
CFP/CFP2/CFP4
(CFP4 doesn’t support SR10)
SR10
100m
MPO24
10*10G
850nm
MMF
LR4
10km
Dual LC
4*25G
1310nm
SMF
ER4
40km
Dual LC
4*25G
1310nm
SMF
ZR4
80km
Dual LC
4*25G
1310nm
SMF
QSFP28
SR4
100m
MPO12
4*25G
850nm
SMF
LR4
10km
LC
4*28G
1310nm
SMF
ER4
40km
LC
4*25G
1310nm
SMF
ZR4
80km
LC
4*25G
1310nm
SMF
CWDM4
2km
Dual LC
4*25G
1310nm
SMF
PSM4
2km
MPO
4*25G
1310nm
SMF


Conclusion 


Learning the contents of the 100G light module, above, do you have any further information? From the development trend, QSFP28 optical transceiver and CFP series optical transceiver are 100G network hot solutions, and the use of CXP will be less and less. Gigalight, as a veteran optical transceiver manufacturer with professional technology, advanced R & D capability and stable manufacturing capability, not only has many popular 100G optical transceiver products, like 100G QSFP28 CWDM4, 100G QSFP28 PSM4, CFP2 100G LR4, and etc. but also will release more new 100G optical transceivers in the first quarter of this year. More information about 100G optical transceivers, please visit the official website.


2018-01-29

The Key Technology for 100G CFP/CFP2 LR4 Optical Transceiver

The form factors of 100G CFP optical modules can be divided into CFP/CFP2/CFP4, and they can be divided into 100GBASE-SR10, 100GBASE-LR4, and 100GBASE-ER4 according to the transmission distance. All optical module transmission distance is decided by the optical output signal OSNR tolerance and chromatic dispersion tolerance decision. Generally speaking, it is determined by the laser and its drive performance.

At present, there are two types of optical modulation methods for implementing CFP 100GBASE-LR4 transmission in the mainstream market. One is a Direct Modulation Laser Modulation (DML) mode, that is, a direct modulation laser. And another one is an Electlro -Modulation Modulation (EML) mode, that is, modulation laser.
The following post will briefly introduce some key technical points of using the TEC circuit and EML modulation mode to realize the 100G CFP / CFP2 LR4 optical transceivers.

1. TEC Circuit


EML lasers need to work at a certain wavelength, the temperature jump will lead to a temperature drift effect, resulting in wavelength instability, drifting, so the stable working conditions of the laser is a relatively stable operating temperature (steady wavelength) This requires that we have to provide a high-precision TEC circuit, that is, a semiconductor refrigerator. The TEC is actually a PN junction made of two semiconductors of different materials. When a direct current passes through the PN junction, electrons and gaps in the two materials The hole produces an endothermic or exothermic effect during movement across the PN junction, effecting a cooling or heating laser effect, and TEC heating or cooling can be controlled by changing the current direction and size.



A high-precision op amp compares the target temperature we set with the temperature fed back by the thermistor, and the error voltage is amplified by a high-gain amplifier while compensating for the network's contribution to the hot and cold ends of the laser The phase delay is compensated to drive the H-bridge output to control the size and direction of the TEC current. When the temperature drops below our target temperature, the H-bridge will reduce the TEC current or change the direction of the TEC current for cooling. Conversely, the final control loop Road will reach a dynamic equilibrium, the temperature will stabilize. Among them, the compensation circuit is the most critical part of the TEC temperature control circuit, that is PID proportional integral differential adjustment compensation network, which determines the TEC controller response speed and regulation accuracy.

2. EAM Regulation


EML lasers are essentially integrated devices for EAM (Electroabsorption Modulator) and LD (DFB lasers). The key core is the EML chip, which is the core of an electro-absorption modulated laser based on the Stark Effect (QCSE) design. The DML laser modulates the light intensity by directly controlling the laser current, which always works in an unstable state and is easily influenced by the outside world. In contrast, the EML laser mainly controls the optical signal by controlling the EAM, the light source will be more stable, and the transmission Relatively speaking, the characteristics and transmission effects will be better, especially in high frequency modulation and long distance.



In application, the LD pin injects a constant current to the laser to make the laser emit light, and the EAM changes the ratio of the laser light to obtain different intensity of light. The development of Ethernet technology has gone through a number of development stages from low speed to high speed.

The rate of development from 1M, 10M, 100M and 1G to 10G and 100G has led to more demand for it to evolve to a higher rate. I believe there will be new technologies have emerged to meet the growing demand for optical modules.


2018-01-21

Advantages of 100G CFP4 Optical Transceivers


With the network market gradually develop from 10G to 40G and 100G, 40G/100G optical devices are also widely used in various fields. In the next few years, 100G products will continue to be popularized and gradually accepted by the market. 100G CFP series optical transceivers are available in three different package sizes: CFP, CFP2, CFP4 optical transceivers.

The 100G CFP optical transceiver is also known as 100G client module, which is a form factor pluggable module that supports hot plugging. CFP series of optical transceivers from the launch to now experienced a total of CFP, CFP2 development, and now, CFP4 optical transceiver has been successfully introduced and widely acclaimed. Compared with CFP / CFP2 optical transceiver, 100G CFP4 optical transceiver has the same rate but the transmission efficiency has greatly improved. Besides, the power consumption is reduced and the cost is lower than CFP2. CFP4 optical transceiver has irreplaceable advantages. We will talk about it in the second part.

Advantages of CFP4 Optical Transceiver:


Compared with the traditional CFP, CFP2 series, CFP4 optical transceiver has obvious advantages.

Smaller size: CFP4 optical transceiver is one-half of that of CFP2, which is one quarter of CFP. It is the smallest optical transceiver in CFP series optical transceiver.

Higher transmission efficiency: The early 100G CFP optical transceiver in 10 * 10 mode, through 10 10G channels, to 100G transmission rate, but the current 100G CFP4 optical transceiver with 4 * 25 mode, through 4 25G channel, to achieve 100G transmission, transmission more efficient and more stable.

Module integration is higher: CFP2 integration is 2 times CFP, CFP4 integration is four times CFP.

Lower power consumption and cost: CFP4 optical transceiver is compatible with MSA protocol and supports the same speed as CFP2 and CFP2s. The transmission efficiency is obviously improved, but the power consumption drops drastically, only about half of the original, and the system cost is more than that of CFP2 low.


As we all know, 100G is the future trend of network development. With the expansion of the 100G industry, the cost of a 100G optical transceiver will also be reduced correspondingly, thereby reducing the cost of deploying the entire 100G network. Gigalight believes that CFP4 series optical transceivers for 100G applications brought will promote the 100G faster development. 

2018-01-08

How Much Do You Know about 100G Optical Transceivers

In recent years, with the rapid growth of users' demand for transmission links of 40G and 100G optical transceivers, cloud computing, mobile broadband and IPTV users have also increasingly requested bandwidth. 40G links have been deployed for several years now and 40G optical transceivers are ubiquitous in the data center. In the past two years, 100G optical transceivers have been rapidly developed in the Data Center market due to the development of optical industry centered on "100G network deployment." At present, 100G optical transceivers on the market mainly include: CXP optical transceiver, CFP optical transceiver, CFP2 optical transceiver, CFP4 optical transceiver and QSFP28 optical transceiver. Here we are going to introduce you the several main types of 100G optical transceivers. How much do you know about 100G optical transceivers? The post may give you an answer.

 1. CXP Optical Transceiver


CXP optical transceiver transmission rate is up to 12 × 10Gbps and supports hot swappable. "C" stands for 12 in hexadecimal, Roman "X" stands for 10 Gbps for each channel, and "P" for a hot pluggable pluggable. The CXP optical transceivers are targeted at the high-speed computer market and complement the CFP optical transceivers in Ethernet data centers. Technically, CFP optical transceivers and multimode fiber are both used for short-distance data transmission. Since multimode fiber markets require high-density panels, their dimensions have not been truly optimized in the multimode fiber market.

CXP optical transceiver is 45 mm long and 27 mm wide. It has a larger size than XFP optical transceiver or CFP optical transceiver and therefore it provides a higher density network interface. In addition, CXP optical transceiver is a copper connector system designated by the Wireless Broadband Trade Association that supports 12 ports for 100 GbE, 3 10G link for 40 GbE or 12 10GbE Fiber Channel or 12 × QDR link transmission of wireless broadband signals.

2. CFP / CFP2 / CFP4 Optical Transceiver


The CFP Multi-Source Agreement (MSA) defines the requirements for hot-pluggable optical transceivers that are used for 40G and 100G network transmission, including next-generation high-speed Ethernet (40GbE and 100GbE). CFP optical transceiver supports transmission on a single-mode and multi-mode fiber at a variety of rates, protocols, and link lengths, including all the physical media dependent (PMD) interfaces in the IEEE 802.3ba standard. 100G network has three PMDs: CFP 100GBASE-SR10 can transmit 100m, CFP 100GBASE-LR4 can transmit 10km, CFP 100GBASE-ER4 can transmit 40km.

CFP optical transceiver is based on the Small Form Factor Pluggable Optical transceiver (SFP) interface and is larger in size to support 100Gbps data transmission. The electrical interface for the CFP optical transceiver uses 10 x 10 Gbps channels for transmission in each direction (RX, TX) and therefore supports 10 x 10 Gbps and 4 x 25 Gbps interworking. CFP optical transceiver can support a single 100G signal, OTU4, one or more 40G signals, OTU3 or STM-256 / OC-768.

Although CFP optical transceiver can achieve 100G data applications, but its large size can no longer meet the needs of high-density data center. In this case, the CFP-MSA committee defines two other forms: CFP2 and CFP4 optical transceivers. The figure below shows the size comparison of CFP, CFP2 and CFP4 optical transceivers:

3. QSFP28 Optical Transceiver


Similarly, as a small size 100G optical transceiver, QSFP28 optical transceiver is also receiving more and more attention. As its name implies, the QSFP28 optical transceiver has the same design philosophy as the QSFP optical transceiver. The first generation QSFP optical transceiver has four Tx and Rx ports with a rate of 10 Gbps per channel. For QSFP28 optical transceivers, QSFP optical transceivers can send and receive up to 28 Gbps of data per channel. Compared with CFP4 optical transceiver, QSFP28 optical transceiver size is smaller than CFP4 optical transceiver only. Although the QSFP28 optical transceiver offers a density advantage over the CFP4 optical transceiver, the higher maximum power consumption of the CFP4 optical transceiver gives it an advantage over longer distances for optical transmission. There are many kinds of 100G QSFP28 optical transceivers in the market, among them; QSFP28 CWDM4 and QSFP28 PSM4 are the latest most popular optical transceiver modules that are widely used for Data Center.

 

4. CPAK Optical Transceiver


There is another 100G optical transceiver called CPAK on the market. The CPAK optical transceiver is the new module type popular this year. The appearance is similar to the Cisco optical transceiver, but the interface uses the IEEE standard and supports compatibility with other interfaces.


100G optical transceivers are available in a wide range of options. In addition, 100G AOC (Active Optical Cable) will also be introduced to the market for short-distance interconnection and 100G migration applications, which will challenge 100G optical transceivers. At the same time, with the rapid development of technology, 100G optical transceivers will become more cost-effective, and 100G network applications will be getting closer and closer to us. For more details about 100G optical transceivers, please contact us.

2017-12-19

What Is 25G Gigabit Ethernet and Its Advantages

The well-known Ethernet upgrade path is 10G-40G-100G. However, a new research report shows that the latest server upgrade path will be 10G-25G-100G, and it can be upgraded to 400G in the future. But why is it 25G? Because it is a big jump from 10G to 40G, and the fact is that the incremental cost of upgrading from 10G to 25G are not high. We need to support this new Ethernet rate with upgraded cable and optical modules, which will undoubtedly drive the development of QSFP28 and SFP28 optical modules.

An Emerging Standard - 25GbE


In July 2014, 25G Gigabit Ethernet (25GbE) passed the first level of the IEEE agency and successfully completed the Intent Call (CFI). 25G Ethernet is a recommended new Ethernet standard for cloud computing and enterprise data centers. The 25GbE uses four optical fibers in parallel with paired copper cables to achieve a 100G Ethernet transfer rate over four 25-Gbit / s lanes.

Why to Select 25G Gigabit Ethernet?


Compared to the existing 40G standard, 25GbE technology value has been very clear. The 25GbE provides greater port density and lower unit costs for rack server bandwidth connections. For the applications requiring high end-of-line throughput, 25G uses two lanes to 50G compared to four lanes to achieve 40, which is a better choice both for connectivity and physical channel efficiency.

The 25GbE standard uses biaxial copper cables and provides up to 2.5x faster performance per SerDes channel over the existing 10G and 40G. The 50G Ethernet connection uses two switches or network card SerDes channels running at 25 Gb / s, delivering 25% more bandwidth than the 40G and using only four biaxial copper cables, half the 40G. With a single switch / network card SerDes channel, the 25GbE connection provides 2.5 times the 10GbE bandwidth using the same number of SFP + Direct Attach Cables (DAC).

The biggest benefit that 25GbE technology brings to data center operators is the ability to maximize bandwidth and port density with 1U of panel space. It can also implement 100GbE with 25Gb / s single physical layer technology.



25G Ethernet Drives the Development of QSFP28 and SFP28 Optical Modules


QSFP28 applies to 4x25GE access ports and SFP28 for a single 25GE access port. SFP28 module, based on SFP + package, supports 25G Ethernet standard. The SFP28 delivers 25Gb / s transmission with up to 100 meters in over four types of multimode fiber without error code and can be used in high-density 25G Ethernet switches and network interfaces to facilitate data center server connectivity. It applies the popular SFP+ form factor, offering enterprises a more cost-effective solution to upgrade 10G Ethernet connectivity.

QSFP28 (25G Quad Small Form-factor Pluggable) module and interconnect cable are high-density, high-speed product solutions, which is designed for optical communication, data center and networking market applications. It provides four high-rate signaling channels that can grow from 25Gbps to 40Gbps and will meet the 4X wireless bandwidth-enhanced data rate (EDR) requirements of 100 Gbps Ethernet (4x25 Gbps).

The below photo is the QSFP28 100GBASE-SR4 by Gigalight. The QSFP28 SR4 optical module is a vertically integrated solution that meets the IEEE802.3 standard and MSA requirements while power consumption is significantly lower than 2.5W. This module supports breakthrough applications of the 100GBASE-SR4 standard and IEEE 802.3bm.


 Conclusion


25G will be the dominant next-generation server connection speed standard because it offers mainstream customers a long-term cost advantage. Compared to the existing 40G standard, 25GbE technology value has been very clear. The 25GbE provides greater port density and lower unit costs for rack server bandwidth connections. For applications requiring high end-of-line throughput, 25G uses two lanes to 50G compared to four lanes to achieve 40, which is a better choice both for connectivity and physical channel efficiency.


2017-12-12

Types and Standards of 100G Optical Transceivers

As people demand higher and higher bandwidth, 100G networks has been developed rapidly. 100G optical module is an important part of 100G network. Now, there are several important standards and types of 100G optical transceivers. This post will introduce the related knowledge of 100G optical module in detail.

Types of 100G Optical Transceivers


The form factors of 100G optical transceivers mainly include: CFP, CFP2, CFP4 and QSFP28. To compare their advantages, the main factor to consider is the data center costs and power consumption.

1. CFP optical transceiver supports all C-band wavelengths tunable. It is able to complete the link detection by using a common optical dual binary modulation format ODB. The power consumption is less than 24W.

2. The volume of CFP2 optical module is one-half the CFP, whose integration is 2 times of CFP. It can complete the wide dynamic input range based on SOA to achieve stable admission sensitivity. It supports a full CFP optical module and its low power consumption is lower than 9W.

3. The volume of CFP4 optical transceiver is one-half the CFP2’s, its integration is twice that of CFP2. The front panel port density is also doubled compared with CFP2. CFP4 optical module MSA protocol supports the same rate of CFP2 and CFP2s. The transmission power has increased significantly, but the power consumption has dropped significantly, only about half of the original, the system cost is lower than the CFP2. In addition, CFP4 optical module select 4 * 25 form, through the 425G channel to complete 100G transmission, higher transmission power, more stable.

4. QSFP28 optical transceiver module form factor style is smaller than the CFP4 optical module. QSFP28 optical module power consumption is generally not more than 3.5W; the use of QSFP28 optical module can directly upgrade through the 40G to 100G, the cost is lower. There are all kinds of 100G QSFP28 optical transceivers in the market, like QSFP28 100GBASE-CWDM4, QSFP28 100GBASE-PSM4, QSFP28 100GBASE-SR4, and QSFP28 100GBASE-LR4, etc.



100G Optical Transceiver Standard


Since the coming of 100G networks, IEEE, Multi-SAource Agreement (MSA) industry alliances and other agencies have formulated a number of standards for 100G optical modules. Among the many standards, the PSM4 and CWDM4 standards are developed by the Multi-Source Agreement (MSA) industry group, which are more suitable for the mainstream 100G QSFP28 optical modules on the market today. The following table is the specific circumstances of some common 100G optical transceiver standard:


Note:

The 100G PSM4 standard is introduced primarily to reduce the cost of expensive 100GBASE-LR4 optical modules. The 100G PSM4 optical transceiver is a single-mode, parallel, four-channel optical module designed for applications in the data center of 500 meters.

The 100G CWDM4 standard is mainly formulated for the deployment of a 2km 100G link in a data center. The interface of a 100G CWDM4 optical transceiver conforms to the 2km 100G optical interface specification of duplex single mode optical fiber, and the transmission distance can reach 2km.

2017-12-04

An Introduction of 4 Types of 100G QSFP28 Optical Transceivers

The continual rapid development of Internet and people’s desire for more high-speed optical networks promoted the development of the whole optical communication industry. Meanwhile, they strongly promoted the independent R&D and innovation breakthrough of many core technologies including optoelectronic devices technology. 100G optical transceivers are products of the big data era. According to authorities, by 2018, there will be 38% of service providers deploying 100G networks in the whole world, which means the 100G era has arrived.

Therefore, 100G optical transceivers are quite important in the optical networks, in which 100G QSFP28 optical transceivers are regarded as one of the most popular 100G optical transceivers in the current market. In the post, we will introduce you 4 types of 100G QSFP28 optical transceivers that may be helpful for your needs.

1. 100G QSFP28 CWDM4 2KM Optical Transceiver


100G QSFP28 CWDM4 2KM optical transceiver is a 100Gb/s transceiver module which is designed for optical communication applications compliant with the QSFP MSA,CWDM4 MSA and portions of IEEE P802.3bm standard. The optical transceiver module converts 4 input channels of 25Gb/s electrical data to 4 channels of CWDM optical signals and then multiplexes them into a single channel for 100Gb/s optical transmission. On the contrary, the module de-multiplexes a 100Gb/s optical input into 4 channels of CWDM optical signals and then converts them to 4 output channels of electrical data on the receiver side. The product provides superior performance for 100G Ethernet applications up to 2km links.

2. 100G QSFP28 PSM4 2KM Optical Transceiver


100G QSFP28 PSM4 2KM optical transceiver is a four-channel, pluggable, parallel, fiber-optic QSFP28 PSM4 optical transceiver module for 100/40 Gigabit Ethernet and Infiniband DDR/EDR Applications. This optical transceiver integrates four data lanes in each direction with 104 Gbps bandwidth. Each lane can operate at 26Gbps up to 2km by using G.652 SMF. The optical transceiver module is designed to operate over single mode fiber system using a nominal wavelength of 1310nm. The electrical interface uses a 38PIN Edge type connector. The optical interface uses a single mode 12 fiber MTP (MPO) connector. The outstanding circuit and optical technology by Gigalight provide reliable long life, high performance, and consistent service.

3. 100G QSFP28 LR4 10KM Optical Transceiver


The 100G QSFP28 LR4 optical transceiver module is a 100Gb/s transceiver module designed for optical communication applications compliant to 100GBASE-LR4 of the IEEE P802.3ba standard.
The module converts 4 input channels of 25Gb/s electrical data to 4 channels of LAN WDM optical signals and then multiplexes them into a single channel for 100Gb/s optical transmission. Its 100Gb/s high sensitivity PIN receivers provide superior performance for 100Gigabit Ethernet and OUT4 applications up to 10km links and compliant to optical interface with IEEE802.3ba 88 100GBASE-LR4 requirements. The product design and form factor, light/electrical connections and digital diagnostic interfaces are all based on QSFP+MSA protocol.

4. 100G QSFP28 SR4 Optical Transceiver


The 100G QSFP28 SR4 optical transceiver is a four-channel, pluggable, parallel, fiber-optic QSFP+ SR4 optical transceiver module for 100/40 Gigabit Ethernet, Infiniband DDR/EDR and 32GFC applications. This transceiver is a high performance module for short-range multi-lane data communication and interconnects applications. It integrates 4 data lanes in each direction with 112.2 Gbps bandwidth. Each lane can operate at 8.055Gbps up to 70M using OM3 fiber or 100M using OM4 fiber. The module is designed to operate over multimode fiber system using a nominal wavelength of 850nm. The electrical interface uses a 38 contact edge type connector. The optical interface uses an 12 fiber MTP (MPO) connector.


In above, 100G QSFP28 optical transceiver modules have huge market prospect that are better suited for high-density cabling and widely favored by most data centers. And the 4 types of 100G QSFP28 optical transceiver modules are all launched by Gigalight. If you want to get more information, please visit Gigalight official website.

2017-11-29

SFP, SFP + and XFP: What Are the Differences

In current optical communication market, there are various kinds of optical transceivers which come in various form factors at speeds from 100Mbps to 100Gbps and are fully compliant with the MSA and IEEE 802.3 standards. Some of the more popular form factors are SFP, SFP +, XFP, GBIC, QSFP, QSFP28 and QSFP-DD. In this post, we will mainly discuss SFP, SFP + and XFP optical transceivers, the main differences among them will be covered in the following parts.

Definition of SFP:

When we discuss what SFP is, SFP stands for Small Form-Factor Pluggable, a compact, hot-pluggable transceiver that can be used in the ports of telecommunications and data communications equipment. SFP modules are designed to support SONET, Gigabit Ethernet, Fiber Channel and other optical communication standards. Due to its small size and improved performance in conjunction with higher speeds, the module has displaced the universally applicable GBIC transceivers and is therefore sometimes referred to as a mini-GBIC.

As an interchangeable fiber connector that can adapt to any existing network, SFP makes network maintenance a lot easier. SFP transceiver modules allow a higher port density (number of transceivers per cm along the edge of a motherboard). These modules are not standardized by a state agency, but specified by a multi-source agreement (MSA), which has been adopted by various manufacturers. Some network component manufacturers have provided protection to the SFPs, deliberately avoiding compatibility with generic "SFPs" by checking firmware or other areas of programming, whereby only the modules approved by the manufacturer can be used. However, some manufacturers have introduced SFPs with empty programmable EEPROMs that can be reprogrammed to match each supplier ID.

Modern SFP transceiver modules also come with standard Digital Diagnostic Monitoring (DDM) functions, which is also known as Digital Optical Monitoring (DOM). This gives end users the ability to monitor in real time SFP parameters such as optical output, optical input power, temperature, laser current, supply voltage, etc. This functionality can be used to monitor routers, switches, and other optical devices, which can be reprogrammed to match any supplier ID.

Definition of SFP +:

SFP + stands for Small Form-Factor Pluggable Plus. SFP + transceivers are an enhanced version of the SFP that can support data rates up to 16Gbps. The SFP + specification were first published on May 9, 2006 and the first version 4.2 was released on July 6, 2009. As one of the most popular industry standards in optical communication industry, SFP + transceivers are supported by many network component providers. SFP + offers standard 8 Gbps Fiber Channel, 10 Gigabit Ethernet and the Optical Transport Network Standard OTU2.

SFP + transceiver modules have the same dimensions as the SFP. The big difference between the SFP and SFP + modules is the coding method. These modules have more circuitry on the host board than the internal module. SFP + modules can also be used in older devices with XENPAK or X2 ports through the use of an active electronic adapter. SFP + modules come in two types linear and limited. Linear SFP + modules are best for 10GBase-LRM, otherwise limited modules are preferred. These contain a signal amplifier to redesign the degraded (received) signal, whereas linear modules do not.

Definition of XFP:

XFP stands for 10 Gigabit Small Form Factor Pluggable, a hot-swappable and protocol independent module. It enables a fast transmission of data in the computer network. XFP was devised by the XFP Multi-source Agreement Group and first emerged in the year 2002 along with XFI, one of its electrical components.

XFP transceiver modules are protocol-independent and fully compliant to various standards, including: 10G Ethernet, 10G Fibre Channel, SONET OC-192, SDH STM-64 and OTN G.709. It supports bit rate from 9.95G through 11.3G, along with its interface to other electrical components which is called XFI. The 10-Gigabit XFP transceiver module is a hot-swappable I/O device that plugs into 10-Gigabit ports.XFP transceiver modules connects the electrical circuitry of the system with the optical network.

SFP package --- hot-plug small- package module, the highest rate is up to 4G , usually LC interface connect.
SFP + package --- standard package, the working speed can be 10G, the application of 10G Ethernet.
XFP --- standardized package of serial 10G optical transceiver modules.


The Difference between SFP and SFP +:


1. The look and the size of the SFP and SFP + are the same;
2. The highest rate of SFP is up to 4G is the rate of SFP + 10G;
3. The protocol specification of the SFP: SFP: IEEE802.3, SFF-8472;
4. SFP + supports DDM .


The Difference between SFP + and XFP:


1. SFP + and XFP both are 10G optical module , and can be connected with other types of 10G modules;
2. The look and the size of the SFP + is less than XFP;
3. Because of the smaller size, SFP + moves the signal modulation function, serial / deserialization program, MAC, clock and data recovery ( CDR ) and electronic distribution compensation ( EDC ) function to the motherboard card from modules;
4. Compliance agreement of XFP: MSA XFP agreement;
5. Compliance Agreement of SFP +: IEEE 802.3ae, SFF-8431, SFF-8432;
6. SFP + is a mainstream design;
7. The Protocol Specification of SFP +: IEEE 802.3ae, SFF-8431, and SFF-8432.

10G optical module underwent the development of 300Pin, XENPAK, X2, XFP, which finally realize that the transmission of 10G signal with the same size as SFP, this is SFP +. SFP + met the requirements of the high-density optical module, gradually replacing XFP and become the mainstream of the 10G market. People around the world learn the difference between SFP, SFP + and XFP, and avoid unnecessary hassles to the customer, so we provide some information for them.