Things You Must Know: 200G vs. 400G Ethernet in Data Centers

With the rise of high data rate applications such as 5G and cloud computing, 200G and 400G Ethernet are getting much attention in data centers. In most cases, 400G Ethernet is more competitive than 200G Ethernet with regards to the applications in data centers. In this post, we are about to reveal how 400G Ethernet outperforms 200G Ethernet in several aspects.

400G Ethernet vs 200G Ethernet: More Comprehensive Standardization

During the evolution of the IEEE protocol standard, the 200G standard was issued later than the 400G standard. The 400G standard was first proposed in 2013 by IEEE 802.3 Working Group and was approved in 2017 with IEEE 802.3bs 400G Ethernet standard. While the 200G standard was proposed and approved in 2015 and 2018 respectively. And the 200G single-mode specification is generally based on the 400G single-mode specification but halved the 400G one. With the fast upgrades of 400G technology and its products due to market needs, the 400G standard is more comprehensive and maturer than that of 200G.

Common Use of 100G Server Promotes More 400G Ethernet Applications

Network switch speed is always driven by server uplink speed. No matter in the past or at present, one-to-four structure is often used to connect switches and servers to increase the port density of switches. And this structure is likely to be adopted in the future as well. Then, how to choose between the 200G Ethernet and 400G Ethernet mainly depends on the server we use.

How to Connect Servers in Data Centers.jpg

According to Crehan research and forecast, the momentum of 100G servers surpassed that of 50G servers since 2020. That means, most network operators are likely to use 100G server connection rather than 50G. And 100G servers would become the mainstream according to the trends during 2020-2023. In other words, one could skip 200G and choose 400G directly with 100G server deployed.

50G vs 100G Server Adoption Rates.jpg

Optical Transceiver Market Drives 400G Ethernet

There are two main factors that push 400G Ethernet more popular than 200G Ethernet in the optical transceiver market. One is the module supply, another is the cost.

400G Optical Transceivers Gain More Market Supplies and Acceptance

Normally, the early adoption of 400G is to support the rise of 200G long-haul for aggressive DCI network builds. It makes 400G possible in metro networks and supports 3x the distance for 200G wavelengths. WIth further development, 400G transceivers are more favorable among manufacturers. Many suppliers pay more attention to 400G Ethernet rather than 200G. For example, Senko’s new CS connector is specifically designed for 400G data center optimization. Actually, all things have reasons. Even if the total cost of 200G transceiver and 400G transceiver is the same, the cost and power consumption per bit of 400G transceiver is half of the 200G’s because of the doubled bandwidth of 400G. More importantly, the total revenue data among 100G, 200G and 400G shows that 400G is far beyond 200G in the whole market.

Total Revenue for 100G 200G and 400G Transceivers.jpg

According to shipment data of the top 8 suppliers gathered by Omdia, the 400G transceiver market is more prosperous than that of 200G. There are more options for users in 400G deployment. Although the top 8 suppliers all provide 200G and 400G transceivers, 200G transceivers only offer 100m SR4 and 2km FR4 while 400G transceivers could offer more options like SR8 100mDR4 500mFR4 2kmLR4 10km, and ER8 40km, etc. In addition, 400G products, such as 400G DAC and 400G DAC breakout cables and solutions are maturer and more perfect than 200G because of their earlier release.

Supplier SupportFinisarInnolightFITLumentumAccelinkSource PhotonicsAOIHisense
200G SR4      
200G FR4    
400G SR8
400G SR4.2     
400G DR4
400G FR4
400G ZR       

400G Optical Modules Support More Applications With Fewer Cost

Compared to 200G transceivers, 400G transceivers could support more applications including DCI and 200G applications. And they can double the traffic carrying capacity between applications than 100G/200G solutions. With 400G solutions, fewer transponders will be needed, resulting in less transportation and operating costs. This will make the 400G market more lively in return.

400G Ethernet Is more Suitable for Future Network Upgrades

The 200G optical modules will include two main form factors, namely QSFP-DD and CFP2. The 400G optical transceivers will mainly include QSFP-DD and OSFP packages. Since the OSFP is expected to offer a better path to 800G and higher transmission rates, 400G transceiver is more suitable and convenient for future network migration.

Conclusion

From the current analysis and evidence above, 400G Ethernet is more competitive than 200G Ethernet in Ethernet standardization, 100G server connection, optical transceiver market and future network upgrades. There is no need to hesitate between 200G Ethernet and 400G Ethernet. Choosing 400G Ethernet and products is a wise decision not only for the current but for the long-term future.

Article Source

https://community.fs.com/blog/200g-vs-400g-ethernet.html

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How Is 5G Pushing the 400G Network Transformation?

With the rapid technological disruption and the wholesale shift to digital, several organizations are now adopting 5G networks, thanks to the fast data transfer speeds and improved network reliability. The improved connectivity also means businesses can expand on their service delivery and even enhance user experiences, increasing market competitiveness and revenue generated.

Before we look at how 5G is driving the adoption of 400G transformation, let’s first understand what 5G and 400G are and how the two are related.

What is 5G?

5G is the latest wireless technology that delivers multi-Gbps peak data speeds and ultra-low latency. This technology marks a massive shift in communication with the potential to greatly transform how data is received and transferred. The increased reliability and a more consistent user experience also enable an array of new applications and use cases extending beyond network computing to include distributed computing.

And while the future of 5G is still being written, it’s already creating a wealth of opportunities for growth & innovation across industries. The fact that tech is constantly evolving and that no one knows exactly what will happen next is perhaps the fascinating aspect of 5G and its use cases. Whatever the future holds, one is likely certain: 5G will provide far more than just a speedier internet connection. It has the potential to disrupt businesses and change how customers engage and interact with products and services.

What is 400G?

400G or 400G Ethernet is the next generation of cloud infrastructure that offers a four-fold jump in max data-transfer speed from the standard maximum of 100G. This technology addresses the tremendous bandwidth demands on network infrastructure providers, partly due to the massive adoption of digital transformation initiatives.

Additionally, exponential data traffic growth driven by cloud storage, AI, and Machine Learning use cases has seen 400G become a key competitive advantage in the networking and communication world. Major data centers are also shifting to quicker, more scalable infrastructures to keep up with the ever-growing number of users, devices, and applications. Hence high-capacity connection is becoming quite critical.

How are 5G and 400G Related?

The 5G wireless technology, by default, offers greater speeds, reduced latencies, and increased data connection density. This makes it an attractive option for highly-demanding applications such as industrial IoT, smart cities, autonomous vehicles, VR, and AR. And while the 5G standard is theoretically powerful, its real-world use cases are only as good as the network architecture this wireless technology relies on.

The low-latency connections required between devices, data centers, and the cloud demands a reliable and scalable implementation of the edge-computing paradigms. This extends further to demand greater fiber densification at the edge and substantially higher data rates on the existing fiber networks. Luckily, 400G fills these networking gaps, allowing carriers, multiple-system operators (MSOs), and data center operators to streamline their operations to meet most of the 5G demands.

5G Use Cases Accelerating 400G transformation

As the demand for data-intensive services increases, organizations are beginning to see some business sense in investing in 5G and 400G technologies. Here are some of the major 5G applications driving 400G transformation.

High-Speed Video Streaming

The rapid adoption of 5G technology is expected to take the over-the-top viewing experience to a whole new level as demand for buffer-free video streaming, and high-quality content grows. Because video consumes the majority of mobile internet capacity today, the improved connectivity will give new opportunities for digital streaming companies. Video-on-demand (VOD) enthusiasts will also bid farewell to video buffering, thanks to the 5G network’s ultra-fast download speeds and super-low latency. Still, 400G Ethernet is required to ensure reliable power, efficiency, and density to support these applications.

Virtual Gaming

5G promises a more captivating future for gamers. The network’s speed enhances high-definition live streaming, and thanks to ultra-low latency, 5G gaming won’t be limited to high-end devices with a lot of processing power. In other words, high-graphics games can be displayed and controlled by a mobile device; however, processing, retrieval, and storage can all be done in the cloud.

Use cases such as low-latency Virtual Reality (VR) apps, which rely on fast feedback and near-real-time response times to give a more realistic experience, also benefit greatly from 5G. And as this wireless network becomes the standard, the quantity and sophistication of these applications are expected to peak. That is where 400G data centers and capabilities will play a critical role.

The Internet of Things (IoT)

Over the years, IoT has grown and become widely adopted across industries, from manufacturing and production to security and smart home deployments. Today, 5G and IoT are poised to allow applications that would have been unthinkable a few years ago. And while this ultra-fast wireless technology promises low latency and high network capacity to overcome the most significant barriers to IoT proliferation, the network infrastructure these applications rely on is a key determining factor. Taking 5G and IoT to the next level means solving the massive bandwidth demands while delivering high-end flexibility that gives devices near real-time ability to sense and respond.

400G Network

400G Ethernet as a Gateway to High-end Optical Networks

Continuous technological improvements and the increasing amount of data generated call for solid network infrastructures that support fast, reliable, and efficient data transfer and communication. Not long ago, 100G and 200G were considered sophisticated network upgrades, and things are getting even better.

Today, operators and service providers that were among the first to deploy 400G are already reaping big from their investments. Perhaps one of the most compelling features of 400G isn’t what it offers at the moment but rather its ability to accommodate further upgrades to 800G and beyond. What’s your take on 5G and 400G, or your progress in deploying these novel technologies?

Article Source: How Is 5G Pushing the 400G Network Transformation?

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How 400G Has Transformed Data Centers

With the rapid technological adoption witnessed in various industries across the world, data centers are adapting on the fly to keep up with the rising client expectations. History is also pointing to a data center evolution characterized by an ever-increasing change in fiber density, bandwidth, and lane speeds.

Data centers are shifting from 100G to 400G technologies in a bid to create more powerful networks that offer enhanced experiences to clients. Some of the factors pushing for 400G deployments include recent advancements in disruptive technologies such as AI, 5G, and cloud computing.

Today, forward-looking data centers that want to maximize cost while ensuring high-end compatibility and convenience have made 400G Ethernet a priority. Below, we have discussed the evolution of data centers, the popular 400G form factors, and what to expect in the data center switching market as technology continues to improve.

Evolution of Data Centers

The concept of data centers dates back to the 1940s, when the world’s first programmable computer, the Electronic Numerical Integrator and Computer, or ENIAC, was the apex of computational technology. The latter was primarily used by the US army to compute artillery fire during the Second World War. It was complex to maintain and operate and was only operated in a particular environment.

This saw the development of the first data centers centered on intelligence and secrecy. Ideally, a data center would have a single door and no windows. And besides the hundreds of feet of wiring and vacuum tubes, huge vents and fans were required for cooling. Refer to our data center evolution infographic to learn more about the rise of modern data centers and how technology has played a huge role in shaping the end-user experience.data center evolution

The Limits of Ordinary Data Centers

Some of the notable players driving the data center evolution are CPU design companies like Intel and AMD. The two have been advancing processor technologies, and both boost exceptional features that can support any workload.

And while most of these data center processors are reliable and optimized for several applications, they aren’t engineered for the specialized workloads that are coming up like big data analytics, machine learning, and artificial intelligence.

How 400G Has Transformed Data Centers

The move to 400 Gbps drastically transforms how data centers and data center interconnect (DCI) networks are engineered and built. This shift to 400G connections is more of a speculative and highly-dynamic game between the client and networking side.

Currently, two multisource agreements compete for the top spot as a form-factor of choice among consumers in the rapidly evolving 400G market. The two technologies are QSFP-DD and OSFP optical/pluggable transceivers.

OSFP vs. QSFP-DD

QSFP-DD is the most preferred 400G optical form factor on the client-side, thanks to the various reach options available. The emergence of the Optical Internetworking Forum’s 400ZR and the trend toward combining switching and transmission in one box are the two factors driving the network side. Here, the choice of form factors narrows down to power and mechanics.

The OSFP being a bigger module, provides lots of useful space for DWDM components, plus it features heat dissipation capabilities up to 15W of power. When putting coherent capabilities into a small form factor, power is critical. This gives OSFP a competitive advantage on the network side.

And despite the OSFP’s power, space, and enhanced signal integrity performance, it’s not compatible with QSFP28 plugs. Additionally, its technology doesn’t have the 100Gbps version, so it cannot provide an efficient transition from legacy modules. This is another reason it has not been widely adopted on the client side.

However, the QSFP-DD is compatible with QSFP28 and QSFP plugs and has seen a lot of support in the market. The only challenge is its low power dissipation, often capped at 12 W. This makes it challenging to efficiently handle a coherent ASIC (application-specific integrated circuit) and keep it cool for an extended period.

The switch to 400GE data centers is also fueled by the server’s adoption of 25GE/50GE interfaces to meet the ever-growing demand for high-speed storage access and a vast amount of data processing.400G OSFP vs. QSFP-DD

The Future of 400G Data Center Switches

Cloud service provider companies such as Amazon, Facebook, and Microsoft are still deploying 100G to reduce costs. According to a report by Dell’Oro Group, 100G is expected to peak in the next two years. But despite 100G dominating the market now, 400G shipments are expected to surpass 15M million switch ports by 2023.

In 2018, the first batch of 400G switch systems based on 12.8 Tbps chips was released. Google, which then was the only cloud service provider, was among the earliest companies to get into the market. Fast-forward, other cloud service providers have entered the market helping fuel the transformation even further. Today, cloud service companies make a big chunk of 400G customers, but service providers are expected to be next in line.

Choosing a Data Center Switch

Data center switches are available in a range of form factors, designs, and switching capabilities. Depending on your unique use cases, you want to choose a reliable data center switch that provides high-end flexibility and is built for the environment in which they are deployed. Some of the critical factors to consider during the selection process are infrastructure scalability and ease of programmability. A good data center switch is power efficient with reliable cooling and should allow for easy customization and integration with automated tools and systems. Here is an article about Data Center Switch Wiki, Usage and Buying Tips.

Article Source: How 400G Has Transformed Data Centers

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400ZR: Enable 400G for Next-Generation DCI

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400ZR: Enable 400G for Next-Generation DCI

To cope with large-scale cloud services and other growing data center storage and processing needs, the data center systems have become increasingly decentralized and difficult to manage. And applications like artificial intelligence (AI) urgently need low-latency, high-bandwidth network architectures to support the large number of machine-to-machine input/output (I/O) generated between servers. To ensure the basic performance of these applications, the maximum fiber propagation between these distributed data centers must be limited to about 100 km. Therefore, these data centers must be connected in distributed clusters. In order to ensure high-bandwidth and high-density data center interconnection at the same time, 400G ZR came into being. In this post, we will reveal what 400ZR is, how it works and the influences it brings about.

What Is 400ZR?

400ZR, or 400G ZR, is a standard that will enable the transmission of multiple 400GE payloads over Data Center Interconnect (DCI) links up to 80 km using dense wavelength division multiplexing (DWDM) and higher-order modulation. It aims to ensure an affordable and long-term implementation based on single-carrier 400G using dual-polarization 16 QAM (16-state quadrature amplitude modulation) at approximately 60 gigabaud (Gbaud). Developed by Optical Interconnect Forum (OIF), the 400ZR project is essential to facilitate the reduction of the cost and complexity of high-bandwidth data center interconnects and to promote interoperability among optical module manufacturers.

400G ZR

Figure 1: 400G ZR Transceiver in DCI Switch or Router

How Does 400ZR Work?

400G ZR proposes a technology-driven solution for high-capacity data transmission, which could be matched with the 400GE switch port. It uses a unique design of advanced coherent optical technology for small, pluggable form factor modules. Although the product form factor is not specified in the IA (implementation agreement), the companies or groups contributing to the 400ZR have defined this specification to fit the solution. These form factors defined separately by Multi-Source Agreement (MSA) bodies specify compact mechanical transceivers like QSFP-DD and OSFP, which are connectorized and pluggable into a compatible socket in a system platform. That is to say, the compatible 400ZR solutions that come to market will also be interoperable since the OIF and form factor MSAs are industry-wide organizations. And the interoperability of the 400ZR solutions offers the dual benefit of simplified supply chain management and deployment.

400ZR+ for Longer-reach Optical Transmission

Like other 400G transceivers, the pluggable coherent 400ZR solution can support 400G Ethernet interconnection and multi-vendor interoperability. However, it is not suitable for next-generation metro-regional networks that need transmission over 80 km with a line capacity of 400 Gb/s. Under such circumstances, 400ZR+, or 400G ZR+ is proposed. The 400ZR+ is expected to further enhance modularity by supporting multiple different channel capacities based on coverage requirements and compatibility with installed metro optical infrastructure. With 400ZR+, both the transmission distance and line capacity could be assured.

What Influences Will 400ZR Bring About?

Although 400ZR technology is still in its infancy, once it is rolled out, it will have a significant impact on many industries as the following three: hyper-scale data centers, distributed campuses & metropolitan areas and telecommunications providers.

400ZR Helps Cloud and Hyperscale Data Centers Adapt to the Growing Demand for Higher Bandwidth

The development of DCI and 400ZR could help cloud and hyper-scale data centers adapt to the growing demand for higher bandwidth on the network. They could deal with the exponential growth of applications such as cloud services, IoT devices, and streaming video. As time goes by, 400G ZR will contribute more to the ever-growing applications and users for the whole networking.

400ZR Will Support Interconnects in Distributed Data Centers

As is mentioned above, 400ZR technology will support the necessary high-bandwidth interconnects to connect distributed data centers. With this connection, distributed data centers can communicate with each other, share data, balance workloads, provide backup, and expand data center capacity when needed.

400ZR Allows Telecommunications Companies to Backhaul Residential Traffic

400G ZR standard will allow telecommunications companies to backhaul residential traffic. When running at 200 Gb/s using 64 Gbaud signalings and QPSK modulation, 400ZR can increase the range of high loss spans. For 5G networks, 400G ZR provides mobile backhaul by aggregating multiple 25 Gb/s streams. 400ZR helps promote emerging 5G applications and markets.

400ZR+/400ZR- Will Provide Greater Convenience Based on 400ZR

In addition to the interoperable 400G mode, the 400ZR transceiver is also expected to support other modes to increase the range of addressable applications. These modes are called 400ZR + and 400ZR-. “+” indicates that the power consumption of the module exceeds the 15W required by IA and some pluggable devices, enabling the module to use more powerful signal processing technology to transmit over distances of hundreds of kilometers. “-” indicates that the module supports low-speed modes, such as 300G, 200G, and 100G, which provide network operators with more flexibility.

Will 400ZR Stay Popular In the Next Few Years?

According to the data source below from LightCounting, 400ZR will lead the growth of optical module sales in 2021-2024. The figure below shows the shipment data of high-speed (100G and above) and low-speed (10G and below) DWDM modules sold on the market. It is clear that modules used in Cloud or DCI have an increasing tendency in 2021-2024. That means 400ZR will lead annual growth from 2021.

Source

In addition, with the first 100Gbps SerDes implementation in switching chips expected in 2021, the necessary data rate will move to 800 Gbps within the next 1-2 years for the optics interface. Since the OSFP form factor has been defined to allow an 8x 100GE interface without changing the definition of the transceiver. Similarly, in parallel, the coherent optics on the line side will transition to support 128GBaud 16QAM within a similar time frame, making it easy to migrate from the current 400ZR to the next-generation 800ZR. Therefore, 400ZR is crucial no matter in the current or the future network development.

Article Source

https://community.fs.com/blog/400zr-enable-400g-for-next-generation-dci.html

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400G Data Center Deployment Challenges and Solutions

As technology advances, specific industry applications such as video streaming, AI, and data analytics are increasingly pushing for increased data speeds and massive bandwidth demands. 400G technology, with its next-gen optical transceivers, brings a new user experience with innovative services that allow for faster and more data processing at a time.

Large data centers and enterprises struggling with data traffic issues embrace 400G solutions to improve operational workflows and ensure better economics. Below is a quick overview of the rise of 400G, the challenges of deploying this technology, and the possible solutions.

The Rise of 400G Data Centers

The rapid transition to 400G in several data centers is changing how networks are designed and built. Some of the key drivers of this next-gen technology are cloud computing, video streaming, AI, and 5G, which have driven the demand for high-speed, high-bandwidth, and highly scalable solutions. The large amount of data generated by smart devices, the Internet of Things, social media, and other As-a-Service models are also accelerating this 400G transformation.

The major benefits of upgrading to a 400G data center are the increased data capacity and network capabilities required for high-end deployments. This technology also delivers more power, efficiency, speed, and cost savings. A single 400G port is considerably cheaper than four individual 100G ports. Similarly, the increased data speeds allow for convenient scale-up and scale-out by providing high-density, reliable, and low-cost-per-bit deployments.

How 400G Works

Before we look at the deployment challenges and solutions, let’s first understand how 400G works. First, the actual line rate or data transmission speed of a 400G Ethernet link is 425 Gbps. The extra 25 bits establish a forward error connection (FEC) procedure, which detects and corrects transmission errors.

400G adopts the 4-level pulse amplitude modulation (PAM4) to combine higher signal and baud rates. This increases the data rates four-fold over the current Non-Return to Zero (NRZ) signaling. With PAM4, operators can implement four lanes of 100G or eight lanes of 50G for different form factors (i.e., OSFP and QSFP-DD). This optical transceiver architecture supports transmission of up to 400 Gbit/s over either parallel fibers or multiwavelength.

PM4
PAM4

Deployment Challenges & Solutions

Interoperability Between Devices

The PAM4 signaling introduced with 400G deployments creates interoperability issues between the 400G ports and legacy networking gear. That is, the existing NRZ switch ports and transceivers aren’t interoperable with PAM4. This challenge is widely experienced when deploying network breakout connections between servers, storage, and other appliances in the network.

400G transceiver transmits and receives with 4 lanes of 100G or 8 lanes of 50G with PAM4 signaling on both the electrical and optical interfaces. However, the legacy 100G transceivers are designed on 4 lanes of 25G NRZ signaling on the electrical and optical sides. These two are simply not interoperable and call for a transceiver-based solution.

One such solution is the 100G transceivers that support 100G PAM4 on the optical side and 4X25G NRZ on the electrical side. This transceiver performs the re-timing between the NRZ and PAM4 modulation within the transceiver gearbox. Examples of these transceivers are the QSFP28 DR and FR, which are fully interoperable with legacy 100G network gear, and QSFP-DD DR4 & DR4+ breakout transceivers. The latter are parallel series modules that accept an MPO-12 connector with breakouts to LC connectors to interface FR or DR transceivers.

NRZ & PM4
Interoperability Between Devices

Excessive Link Flaps

Link flaps are faults that occur during data transmission due to a series of errors or failures on the optical connection. When this occurs, both transceivers must perform auto-negotiation and link training (AN-LT) before data can flow again. If link flaps frequently occur, i.e., several times per minute, it can negatively affect throughput.

And while link flaps are rare with mature optical technologies, they still occur and are often caused by configuration errors, a bad cable, or defective transceivers. With 400GbE, link flaps may occur due to heat and design issues with transceiver modules or switches. Properly selecting transceivers, switches, and cables can help solve this link flaps problem.

Transceiver Reliability

Some optical transceiver manufacturers face challenges staying within the devices’ power budget. This results in heat issues, which causes fiber alignment challenges, packet loss, and optical distortions. Transceiver reliability problems often occur when old QSFP transceiver form factors designed for 40GbE are used at 400GbE.

Similar challenges are also witnessed with newer modules used in 400GbE systems, such as the QSFP-DD and CFP8 form factors. A solution is to stress test transceivers before deploying them in highly demanding environments. It’s also advisable to prioritize transceiver design during the selection process.

Deploying 400G in Your Data Center

Keeping pace with the ever-increasing number of devices, users, and applications in a network calls for a faster, high-capacity, and more scalable data infrastructure. 400G meets these demands and is the optimal solution for data centers and large enterprises facing network capacity and efficiency issues. The successful deployment of 400G technology in your data center or organization depends on how well you have articulated your data and networking needs.

Upgrading your network infrastructure can help relieve bottlenecks from speed and bandwidth challenges to cost constraints. However, making the most of your network upgrades depends on the deployment procedures and processes. This could mean solving the common challenges and seeking help whenever necessary.

A rule of thumb is to enlist the professional help of an IT expert who will guide you through the 400G upgrade process. The IT expert will help you choose the best transceivers, cables, routers, and switches to use and even conduct a thorough risk analysis on your entire network. That way, you’ll upgrade appropriately based on your network needs and client demands.
Article Source: 400G Data Center Deployment Challenges and Solutions
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Silicon Photonics: Next Revolution for 400G Data Center

400G

With the explosion of 5G applications and cloud services, traditional technologies are facing fundamental limits of power consumption and transmission capacity, which drives the continual development of optical and silicon technology. Silicon photonics is an evolutionary technology enabling major improvements in density, performance and economics that is required to enable 400G data center applications and drives the next-generation optical communication networks. What is silicon photonics? How does it promote the revolution of 400G applications in data centers? Please keep reading the following contents to find out.

What Is Silicon Photonics Technology?

Silicon photonics (SiPh) is a material platform from which photonic integrated circuits (PICs) can be made. It uses silicon as the main fabrication element. PICs consume less power and generate less heat than conventional electronic circuits, offering the promise of energy-efficient bandwidth scaling.

It drives the miniaturization and integration of complex optical subsystems into silicon photonics chips, dramatically improving performance, footprint, and power efficiency.

Conventional Optics vs Silicon Photonics Optics

Here is a Technology Comparison Chart between Conventional Optics vs Silicon Photonics Optics, taking QSFPDD DR4 400G module and QDD DR4 400G Si for example:

The difference between a 400GBASE-DR4 QSFP-DD PAM4 optical transceiver module and a silicon photonic one just lies in: 400G silicon photonic chips — breaking the bottleneck of mega-scale data exchange, showing great advantages in low power consumption, small footprint, relatively low cost, easiness for large volume integration, etc.

Silicon photonic integrated circuits provide an ideal solution to realize the monolithic integration of photonic chips and electronic chips. Adopting silicon photonic design, a QDD-DR4-400G-Si module combines high-density & low-consumption, which largely reduces the cost of optical modules, thereby saving data center construction and operating expenses.

Why Adopt Silicon Photonics in Data Centers?

To Solve I/O Bottlenecks

The world’s growing data demand has caused bandwidths and computing power resources in data centers to be used up. Chips have to become faster when facing the growing demand for data consumption, which can process information faster than the signal can be transmitted in and out. That is to say, chips are becoming faster, but the optical signal (coming from the fiber) must still be converted to an electronic signal to communicate with the chip sitting on a board deep in the data center. And since the electrical signal still needs to travel some distance from the optical transceiver, where it was converted from light, to the processing and routing electronics — we’ve reached a point where the chip can process information faster than the electrical signal can get in and out of it.

To Reduce Power Consumption

Heating and power dissipation are enormous challenges for the computing industry. Power consumption will directly translate to heat. Power consumption causes heat, so what causes power dissipation? Mainly, data transmissions. It’s estimated that data centers have consumed 200TWh each year — more than the national energy consumption of some countries. Thus, some of the world’s largest Data Centers, including those of Amazon, Google, and Microsoft are located in Alaska and similar-climate countries due to the cold weather.

To Save Operation Budget

At present, a typical ultra-large data center has more than 100,000 servers and over 50,000 switches. The connection between them requires more than 1 million optical modules with around US$150 million-US$250 million, which accounts for 60% of the cost of the data center network, exceeding the sum of equipment such as switches, NICs, and cables. The high cost forces the industry to reduce the unit price of optical modules through technological upgrades. The introduction of fiber optic modules adopting Silicon Photonics technology is expected to solve this problem.

Silicon Photonics Applications in Communication

Silicon photonics has proven to be a compelling platform for enabling next-generation coherent optical communications and intra-data center interconnects. This technology can support a wide range of applications, from short-reach interconnects to long-haul communications, making a great contribution to next-generation networks.

  • 100G/400G Datacom: data centers and campus applications (to 10km)
  • Telecom: metro and long-haul applications (to 100 and 400 km)
  • Ultra short-reach optical interconnects and switches within routers, computers, HPC
  • Functional passive optical elements including AWGs, optical filters, couplers, and splitters
  • 400G transceiver products including embedded 400G optical modules400G DAC Breakout cables, transmitters/receivers, active optical cables (AOCs), as well as 400G DACs.

Now & Future of Silicon Photonics

Yole predicted that the silicon optical module market would grow from approximately US$455 million in 2018 to around US$4 billion in 2024 at a CAGR of 44.5%. According to Lightcounting, the overall data communication high-speed optical module market will reach US$6.5 billion by 2024, and silicon optical modules will account for 60% (3.3% in 20 years).

Intel, as one of the leading Silicon photonics companies, has a 60% market share in silicon photonic transceivers for datacom. Indeed, Intel has already shipped more than 3 million units of its 100G pluggable transceivers in just a few short years, and is continuing to expand its Silicon Photonics’ product offerings. And Cisco acquired Accacia for US$2.6 billion and Luxtera for US$660 million. Other companies like Inphi and NeoPhotonics are proposing silicon photonic transceivers with strong technologies.

Original Source: Silicon Photonics: Next Revolution for 400G Data Center

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400G OTN Technologies: Single-Carrier, Dual-Carrier and Quad-Carrier

400G

In order to achieve 400G long-haul (LH) transmission, three 400G Optical Transport Network (OTN) technologies come into being to meet the needs: single-carrier 400G, dual-carrier 400G, and quad-carrier 400G. They differ from each other mainly in the number of wavelengths used for transmission. This post will reveal what they are and their respective pros and cons.

Single-Carrier for 400G OTN

Single-carrier 400G, or single-wavelength 400G, means there is 400G capacity on a single wavelength. The single-carrier 400G adopts high-order modulation formats such as PM-16QAM, PM-32QAM and PM-64QAM. Normally, a single-carrier for 400G optical transport network is used only in network access, metro, or DCI (Data Center Interconnection) transmission.

Single-Carrier for 400G OTN

Figure 1: Single-Carrier for 400G OTN

Take PM-16QAM (Polarization-Multiplexed-16 Quadrature Amplitude Modulation) as an example. PM refers to a process where the 400G (448Gbit/s) optical signal is separated into two signals and modulated to transmit in two polarization directions – X and Y, which can cut the original signal rate in half (224Gbit/s). QAM is a process of separating the signals in X and Y to further reduce the rate. 16 stands for 4 bits, which means the signal in X and Y is respectively divided into 4 signals and the rate will accordingly decrease to 1/4 on the basis of the previous 224Gbit/s. By using PM-16QAM, the signal rate at this moment becomes 56G Baud (the rate of electrical processing).

Note: Because in current circuit technology, 100Gbit/s has approached the limit of the electronic bottleneck. If the Baud continues to increase, problems like signal loss, power dissipation, and electromagnetic interference will remain a hassle, which will, even if solved, require tremendous costs.

PM-16QAM

Figure 2: PM-16QAM

Pros of Single-Carrier for 400G Optical Transport Network

  • Compared with the multi-carriers scheme, single-carrier 400G is an easier wavelength allocation solution with simpler structure and smaller size that can provide easy network management and low power consumption.
  • With higher-order QAM, single-carrier for 400G OTN network can increase signal rates and spectrum efficiency, which will significantly expand network capacity and increase the number of users to support.
  • Also, with high system integration, it can connect the separate subsystems into a complete one and make them work in coordination with each other and achieve the best overall performance.

Cons of Single-Carrier for 400G Optical Transport Network

Since single-carrier for 400G OTN network adopts more advanced QAM, it requires a higher OSNR (Optical Signal Noise Ratio) and greatly reduces transmission distance (less than 200km). Also, single-carrier is more susceptible to laser phase noise and fiber nonlinear effects. Therefore, it is the best solution only for some specific applications that don’t require ultra long-haul transmission distance, but need large bandwidth capacity.

Dual-Carrier for 400G OTN

Dual-carrier 400G, also named dual-wavelength 400G, offers 400G capacity via two 200G wavelengths. The dual-carrier 400G system based on the 2× 200G super-channel scheme adopts lower-order modulation formats like PM-QPSK (Quadrature Phase Shift Keying, a symbol represents two bits, which means the rate is reduced to 1/2), PM-8QAM or PM-16QAM. Dual-carrier for 400G optical transport network is applied in more complex metro networks to achieve 400G long-haul transmission.

Dual-Carrier for 400G OTN

Figure 3: Dual-Carrier for 400G OTN

Pros of Dual-Carrier for 400G Optical Transport Network

  • The spectrum efficiency of dual-carrier 400G has increased by more than 165%, with relatively high system integration, small size, low power consumption. Dual-carrier 400G is regarded as the most commonly-used technology for 400G OTN.
  • The span of dual-carrier 400G is longer than single-carrier 400G, which can reach up to 500km for commercial use. When deployed with low-attenuation fiber optic cable and EDFA (Erbium Doped Fiber Amplifiers), dual-carrier for 400G OTN network can cover more than 1000km, which can basically satisfy the 400G long-haul transmission application.

Cons of Dual-Carrier for 400G Optical Transport Network

Even with low-attenuation fiber optic cable and EDFA, dual-carrier 400G still fails to reach as long as quad-carrier 400G does, not suitable for ultra long-haul (ULH) transmission over 2000km.

Quad-Carrier for 400G OTN

Quad-carrier 400G refers to a solution that offers 400G capacity through four 100G wavelengths. It is achieved by constructing a 400G super-channel based on 100G PM-QPSK with four carriers, suitable for ultra long-haul (ULH) transmission over 2000km.

Quad-Carrier for 400G OTN

Figure 4: Quad-Carrier for 400G OTN

Pros of Quad-Carrier for 400G Optical Transport Network

  • Quad-carrier for 400G OTN network adopts the mature 100G transmission technology that has been widely-used for commercial purpose.
  • It can achieve ultra long-haul transmission of more than 2000km at relatively low cost.

Cons of Quad-Carrier for 400G Optical Transport Network

Quad-carrier 400G system makes sense only when spectrum compression technology is introduced to improve spectrum efficiency, and the 100G chip is upgraded to solve the problems of integration and power consumption. Otherwise, a 400G system built on the current 100G chip is essentially a 100G system.

Conclusion

In all, 400G long-haul transmission is mainly realized by single-carrier, dual-carrier and quad-carrier. Single-carrier for 400G OTN network can only cover a distance of less than 200km; dual-carrier for 400G OTN network is the ideal solution for MAN transmission (with PM-16QAM) and medium long-haul transmission (with PM-QPSK); quad-carrier for 400G OTN network has the same transmission distance as 100G and is appropriate for ULH transmission. As global data traffic keeps climbing, there is no end to bandwidth demands. While it may take time to transit to 400G, you can learn about What’s the Current and Future Trend of 400G Ethernet? to make preparations first.

Original Source: 400G OTN Technologies: Single-Carrier, Dual-Carrier and Quad-Carrier

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400G Optics in Hyperscale Data Centers

Since their advent, data centers have been striving hard to address the rising bandwidth requirements. A look at the stats reveals that 3.04 Exabytes of data is being generated on a daily basis. Whenever a hyperscale data center is taken into consideration, the bandwidth requirements are massive as the relevant applications require a preemptive approach due to their scalable nature. As the introduction of 400G data centers has taken the data transfer speed to a whole new level, it has brought significant convenience in addressing various areas of concern. In this article, we will dig a little deeper and try to answer the following questions:

  • What are the driving factors of 400G development?
  • What are the reasons behind the use of 400G optics in hyperscale data centers?
  • What are the trends in 400G devices in large-scale data centers?

What Are the Driving Factors For 400G Development?

The driving factors for 400G development are segregated into video streaming services and video conferencing services. These services require pretty high data transfer speeds in order to function smoothly across the globe.

Video Streaming Services

Video streaming services were already taking a toll on the bandwidth requirements. That, combined with the COVID-19 pandemic, forced a large population to stay and work from home. This automatically increased the usage of video streaming platforms. A look at the stats reveals that a medium-quality stream on Netflix consumes 0.8 GB per hour. See that in relation to over 209 million subscribers. As the traveling costs came down, the savings went to improved quality streams on Netflix like HD and 4K. What stood at 0.8 GB per hour rose to 3 and 7 GB per hour. This evolved the need for 400G development.

Video Conferencing Services

As COVID-19 made working from home the new norm, video conferencing services also saw a major boost. Till 2021, 20.56 million people have been reported to be working from home in the US alone. As video conferencing took center stage, Zoom, which consumes 500 MB per hour, saw a huge increase in its user base. This also puts great pressure on the data transfer needs.

What Makes 400G Optics the Ideal Choice For Hyperscale Data Centers?

Significant Decrease in Energy and Carbon Footprint

To put it simply, 400G raises the data transfer speed four times. 400G reduces the cost of 100G ports as breakouts when comparing a 4 x 100G solution to facilitate 400GbE with a single 400G solution to do the same. A single node at the output minimizes the risk of failures as well as lower the energy requirement. This brings down the ESG footprint that has become a KPI for the organizations going forward.

Reduced Operational Cost

As mentioned earlier, a 400G solution requires a single 400G port, whereas addressing the same requirement via a 100G solution requires four 100G ports. On a router, four ports cost way more than a single port that can facilitate rapid data transfer. The same is the case with power. Combined together, these two bring the operational cost down to a considerable extent.400G Optics

Trends of 400G Optics in Large-Scale Data Centers—Quick Adoption

The introduction of 400G solution in large-scale data centers has reshaped the entire sector. This is due to a humongous increase in the data transfer speeds. According to research, 400G is expected to replace 100G and 200G deployments way faster than its predecessors. Since its introduction, more and more vendors are upgrading to network devices that support 400G. The following image truly depicts the technology adoption rate.Trends of 400G Optics

Challenges Ahead

Lack of Advancement in the 400G Optical Transceivers sector

Although the shift towards such network devices is rapid, there are a number of implementation challenges. This is because it is not only the devices that need to be upgraded but also the infrastructure. Vendors are trying to upgrade them in order to stay ahead of the curve but the cost of the development and maturity of optical transceivers is not at the expected benchmark. The same is the case with their cost and reliability. As optical transceivers are a critical element, this comes as a major challenge in the deployment of 400G solutions.

Latency Measurement

In addition, the introduction of this solution has also made network testing and monitoring more important than ever. Latency measurement has always been a key indicator when evaluating performance. Data throughput combined with jitter and frame loss also comes as a major concern in this regard.

Investment in Network Layers

Lastly, the creation of a plug-and-play environment for this solution also needs to be more realistic. This will require a greater investment in the physical, higher level, and network-IP components layers.

Conclusion

Rapid technological advancements have led to concepts like the Internet of Things. These implementations require greater data transfer speeds. That, combined with the world going to remote work, has exponentially increased the traffic. Hyperscale data centers were already feeling the pressure and the introduction of 400G data centers is a step in the right direction. It is a preemptive approach to address the growing global population and the increasing number of internet users.

Article Source: 400G Optics in Hyperscale Data Centers

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400G QSFP Transceiver Types and Fiber Connections

400G QSFP has become one of the most popular form factors in the next-generation network. And different types of modules have appeared in the 400G optical transceiver market. What are 400G QSFP-DD transceiver types? What fiber cables could be used with these 400G optical modules? What about the answers to frequently asked questions about 400G QSFP? This post will illustrate them thoroughly.

400G QSFP Transceiver Types

400G QSFP transceivers are introduced respectively in the following table according to the two transmission types (over multimode fiber and single-mode fiber) they support.

Transmission TypeQSFP-DD Product DescriptionReachOptical ConnectorWavelengthOptical ModulationProtocol
Multimode fiber400G QSFP-DD SR8up to 100m over OM4 or OM5
up to 70m over OM3
MTP-16/MPO-16850nm50G PAM4IEEE P802.3cIEEE 802.3cd
Single-mode fiber400G QSFP-DD DR4up to 500m over parallel SMFMTP-12/MPO-121310nm100G PAM4IEEE 802.3bs
400G QSFP-DD XDR4/DR4+up to 2km over parallel SMFMTP-12/MPO-121310nm100G PAM4/
400G QSFP-DD FR4up to 2km over duplex SMFLCCWDM4 wavelength100G PAM4100Glambda MSA
400G QSFP-DD 2FR4up to 2km over duplex SMFCSCWDM4 wavelength50G PAM4IEEE 802.3bs
400G QSFP-DD LR4up to 10km over duplex SMFLCCWDM4 wavelength100G PAM4100Glambda MSA
400G QSFP-DD LR8up to 10km over duplex SMFLCCWDM4 wavelength50G PAM4IEEE 802.3bs
400G QSFP-DD ER8up to 40km over duplex SMFLC1310nm50G PAM4IEEE 802.3cn

Fiber Connections for 400G QSFP Transceivers

QSFP 400G SR8

  • A QSFP-DD SR8 can interop with another QSFP-DD SR8 over an MTP-16/MPO-16 cable. This is the most popular connection using an MTP-16/MPO-16 cable to connect two QSFP-DD SR8 transceivers directly.
  • 400G QSFP-DD SR8 breaks out to 2× 200G SR4.
  • QSFP-DD SR8 interops with 8× 50G SR over MPO-16 to 8× LC duplex fiber cables.

QSFP 400G DR4

  • QSFP-DD DR4 interops with QSFP-DD DR4 over an MPO-12 trunk cable.
    • 400G QSFP-DD DR4 interops with 4× 100G DR over MPO-12 to 4× LC duplex breakout cable.
    QSFP-DD DR4 to 4x 100G Breakout Connection

    QSFP 400G XDR4/DR4+

    • QSFP-DD XDR4/DR4+ interops with QSFP-DD XDR4/DR4+ over an MPO-12 trunk cable.
      • 400G QSFP-DD XDR4 interops with 4× 100G FR modules over an MPO-12 to 4× Duplex LC cable.

      QSFP 400G FR4

      QSFP-DD FR4 interops with QSFP-DD FR4 over a duplex LC cable.

      QSFP-DD FR4 Connection

      QSFP 400G 2FR4

      QSFP-DD 2FR4 interops with 2× 200G FR4 over 2× CS to 2× LC duplex cable.

      QSFP-DD 2FR4 Connection

      QSFP 400G LR4

      QSFP-DD LR4 interops with QSFP-DD LR4 over an LC duplex cable.

      QSFP-DD LR4 Connection

      QSFP 400G LR8

      QSFP-DD LR8 interops with QSFP-DD LR8 over an LC duplex cable.

      QSFP-DD LR8 Connection

      QSFP 400G ER8

      QSFP-DD ER8 interops with QSFP-DD ER8 over an LC duplex cable.

      QSFP-DD ER8 Connection

      400G QSFP Transceivers: Q&A

      Q: What does “SR8”, “DR4”, “XDR4”, “FR4”, “LR4”, and “LR8” mean in QSFP 400G modules?

      A: “SR” refers to short-range, and “8” implies there are 8 optical channels. “DR” refers to 500m reach using single-mode fiber, and “4” implies there are 4 optical channels. “XDR4” is short for “eXtended reach DR4”. And “LR” refers to 10km reach using single-mode fiber.

      Q: Can I plug a QSFP-DD transceiver module into an OSFP port?

      A: No. QSFP-DD and OSFP are totally different form factors. For more information about OSFP transceivers, you can refer to the 400G OSFP Transceiver Types Overview. You can use only one kind of form factor in the corresponding system. Eg, if you have a QSFP 400G system, QSFP-DD transceivers and cables must be used.

      Q: Can I plug a 100G QSFP28 module into a 400G QSFP port?

      A: Yes. A QSFP28 module can be inserted into a QSFP-DD port (without a mechanical adapter). When using a QSFP28 module in a QSFP-DD port, the QSFP-DD port must be configured for a data rate of 100G instead of 400G.

      Q: What other breakout options are possible apart from using the 400G QSFP-DD modules mentioned above?

      A: 400G QSFP-DD DACs & AOCs are possible for breakout 400G connections. See 400G Direct Attach Cables (DAC & AOC) Overview for more information about 400G DACs & AOCs.

      Article Source

      https://community.fs.com/blog/400g-qsfp-dd-transceiver-types-overview.html

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      https://community.fs.com/blog/optical-transceiver-market-200g-400g.html

      https://community.fs.com/news/400g-qsfp-dd-solution-for-400g-data-center-interconnect.html

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      How Much Do You Know About QSFP56?

      Over the past years, there have emerged various optical module form factor types with the growth of new technology and high-speed interconnects, among which QSFP56, as a member of the QSFP family, is a solution for 200G applications. What‘s the difference between QSFP56 with other QSFP family form factors? Is QSFP56 the same as QSFP56-DD? If you are wondering about these questions, this article is for you.

      Figure 1: Transceiver form factor

      QSFP56—Form Factor of 200G Transceivers

      To make clear what QSFP56 is, let’s take a look at the QSFP form factor first. Quad Small Form-Factor Pluggable (QSFP) was developed after SFP, which was originally designed to replace the single-channel SFPs with high-density optical modules. Due to the fact that it denotes four lanes for up to 4 wavelengths, it provides higher bandwidth capacity compared with the SFP modules.

      Developed on the basis of QSFP, 40G QSFP+ arose and then 100G QSFP28 came into use for high-density applications. With the rising of data traffic in data centers and advanced network applications, the market is urgent to achieve higher-speed general availability. There is more addition to QSFP family form factors, such as 200G QSFP56 and 400G QSFP56-DD.

      Figure 2:Types of QSFP form factor

      As an evolution of the previous 40G QSFP+ and 100G QSFP28, Quad 50 Gigabits Small Form-factor Pluggable (QSFP56) is the one designed for 200G Ethernet. QSFP56 denotes 4 x 50 to 56Gb/s in a QSFP form factor. Sometimes it can also be referred to as 200G QSFP for sake of simplicity. QSFP56 optical modules are similar to QSFP ones in terms of size and form factor. Classified by distance, QSFP56 modules can be divided into QSFP56 CR, SR, DR, FR, LR, which enables different transmission distances over a single mode fiber (SMF) or multimode fiber (MMF).

      Generally, two QSFP56 modules can be used with an SMF or MMF to realize a 200G link. QSFP56 AOC/DAC is also a way to realize a 200G link by connecting QSFP56 ports on two devices in a simplified linking process. For bridging 200G QSFP56 ports with other speeds, there are 200G QSFP56 to 2x100G QSFP28 breakout cables and 200G QSFP56 to 4x50G SFP56 breakout cables to achieve 2x100G or 4x50G connections.

      QSFP56 vs QSFP28 vs QSFP+

      Seen from their industry names, QSFP56, QSFP28 and QSFP+ are very similar in that they share the same QSFP form factor as their postfix shows, and they have the same size as each other. However, their data center and connectivity capabilities are different. Below is a table listing the basic parameters of QSFP56, QSFP28, and QSFP+.

      Industry nameYearoriginal meaningNumber of Electric LanesNumber of Optical LanesBit Rate/LaneModulationLine Rates
      QSFP+2013Quad Small Form-factor Pluggable Plus4410GbpsNRZ40G
      QSFP282016Quad Small Form-factor Pluggable 284425GbpsNRZ100G
      QSFP562017Quad 50 Gigabits Small Form-factor Pluggable4450GbpsPAM4200G

      From the comparison chart, it can be distinctly seen that compared with QSFP+ and QSFP28, the QSFP56 form factor performs a higher network speed as 200G QSFP supporting 4×50G channels. While QSFP+ is an evolution of QSFP to support 4×10G channels carrying 10G Ethernet, 10G fiber channel or QDR InfiniBand. It introduced the concept of multiplexing four lanes to increase the bandwidth, capable of handling 40Gbps line rates at 10GBaud NRZ per lane. QSFP28 supports 4×25G channels and contains 4-lane optical transmitter and 4-lane optical receiver as QSFP+ does.

      The most significant change from QSFP+ and QSFP28 to QSFP56 is that QSFP56 made the change from NRZ encoding to PAM4 encoding. Though QSFP56 still uses 4 lanes as QSFP28, the modulation is doubled to 50G per channel, which enables more data on existing fiber, accordingly, more suitable for hyper-scale data center networks.

      Shift from QSFP56 to QSFP56-DD (400G QSFP-DD)

      With data centers undergoing rapid growth, the rising demand for data volume is pushing network components to support higher bandwidth and higher density. The latest iteration of optical module form factor is from QSFP56 to QSFP56-DD, which is also called 400G QSFP-DD. DD here refers to double density, representing reaching 400G (with 50G PAM4) by doubling data lanes of QSFP56, from 4 lanes to 8 lanes.

      Though QSFP56-DD has the double density, its size is similar to QSFP56. 400G QSFP56-DD port is backward compatible with the QSFP transceiver which means as long as the switch supports, QSFP56 can work on the QSFP56-DD port. When using a QSFP56 module in an QSFP56-DD port, this port will be configured for a data rate of 200G, instead of 400G.

      The QSFP56-DD form factor is now recognized by the 400G market as the 400G form factor that gets the most concern. Despite that nowadays 400G Ethernet is seen as a futureproofing solution for the next-generation data center, there is still a need for 200G QSFP56 for some organizations deploying 200G Ethernet.

      Article Source

      https://community.fs.com/blog/introduction-to-qsfp56-form-factor.html

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      https://community.fs.com/blog/400g-qsfp-dd-transceiver-types-overview.html

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