400G Network Archives - Page 3 of 5 - Fiber Optical Networking

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 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?

Typical Scenarios for 400G Network: A Detailed Look into the Application Scenarios

What’s the Current and Future Trend of 400G Ethernet?

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.

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

What’s the Current and Future Trend of 400G Ethernet?

400ZR: Enable 400G for Next-Generation DCI

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.

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
Related Articles:

NRZ vs. PAM4 Modulation Techniques
400G Multimode Fiber: 400G SR4.2 vs 400G SR8
Importance of FEC for 400G

Silicon Photonics: Next Revolution for 400G Data Center

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 modules, 400G 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

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

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.

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.

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.

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.

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