400G Everywhere

400G EverywhereUsing the latest generation of coherent optics to build application-optimized IP-optical networks

INTRODUCTION THE ECONOMICS OF 400G

400G IP-OPTICAL SOLUTIONS

THE DAWN OF THE 400G ERA

IP ROUTING FOR THE 400GE ERA

A 400G AND OPTICAL TECHNOLOGY LEADER

IntroductionThe 400G era has begun. It’s breaking down barriers, radically changing economics and redefining the way IP and optical networks are designed, deployed and delivered.Nokia is leading the way with an unrivalled portfolio of 400G transport solutions that let you create application-optimized IP-optical transport networks your way. These solutions put our game-changing optical technology in your hands and put your IP and optical networks on the same wavelength.

This ebook offers insights that will enhance your understanding of how advances in 400G transport will support the next generation of IP services at 400 Gigabit Ethernet. It also explains how you can implement efficient IP-optical solutions for every application that runs on your network – from the metro edge to subsea communications. Read on to find out how you can benefit from extending 400G everywhere.

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The 400G era promises to unleash a new wave of network innovation. Pluggable coherent transceivers will bring IP and optical together at last, while the latest generation of coherent digital signal processors enables high-performance 400G transmission over any distance.

A new universal currency for IP-optical convergenceWe often speak about exploding traffic growth in terms of annual percentages. Driven by the world’s insatiable appetite for on-demand content and cloud applications, traffic demand grows continuously, exponentially and, as we learned in 2020, sometimes unexpectedly. But the underlying “speeds and feeds” at which network equipment connects and operates grow predictably, even slowly. The data-carrying capacity, or speed, of router and switch ports is gated by the development, standardization and commercialization of Ethernet — Gigabit Ethernet in 1998, 10 Gigabit Ethernet in 2002, 100 Gigabit Ethernet in 2010 and now 400 Gigabit Ethernet (400GE).

Each new rate becomes the currency of high-speed network connectivity and services for a generation, and its adoption is the catalyst for a new network investment cycle. Fed by silicon advances that have enabled massive increases in switching capacity, routers must also move this data into and out of their switch fabric and connect to one another at high speeds and over distance. By combining a fourfold increase in port bandwidth with advances in coherent electro-optics, 400GE promises to unleash a new wave of network innovation that will transform the way IP-optical networks are built and operated. It’s therefore no surprise that a new era of IP-optical integration is poised to emerge alongside the wide adoption of a new Ethernet rate.

The dawn of the 400G era

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https://pages.nokia.com/T005R1-Nokia-Deepfield-Network-Intelligence-Report-Networks-in-2020.html

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We’ve seen these transitions before. Multiple generations of Ethernet have come and gone, accompanied by matching optical wavelength rates, without a major shift toward integrated IP-optical network architectures. One significant obstacle to such integration has been the elevated space and power footprint needed to implement high-speed wavelength division multiplexing (WDM) electro-optics. This has kept operators from using router-based, pluggable WDM optical transceivers as they used packet switching devices to migrate to new, faster Ethernet rates. As a result, operators have continued to use discrete and dedicated optical transponders for WDM transport of IP connections.

However, recent advances in electro-optics, particularly silicon photonics, have bridged this gap by allowing coherent 400G WDM optics to fit within the space and power envelope of high-speed router port form factors. For the first time, these advances coincide

with the new 400GE rate’s expanding adoption and create the potential to integrate the two worlds in the purest of manners – IP, wrapped in Ethernet, launched straight from a router port over an optical wavelength through a pluggable digital coherent optic, or DCO.

A pluggable DCO’s most important attribute is that it can be hosted directly in the router, which removes the space requirements, power consumption and expense of a separate optical transponder. By fitting within the dominant 400GE pluggable form factors, 400G WDM DCOs enable routers to enjoy the same port density when used for WDM transmission over long distances as they do for short reach connectivity. It’s a perfect fit for the burgeoning application of data center interconnection, and it enables necessary scaling of metro networks.






Digital coherent optics and IP-optical integration

400G everywhere (and anywhere)The multiple variants of the latest generation of coherent optics complement one another and are optimized around the economic constraints that predominate within their target network applications. The design trade-offs made by DCOs reflect the short distances, constrained space and power, and plentiful fiber available in metro areas. High-performance coherent optics maximize reach and spectral efficiency where fiber is scarce and operations costly. As they architect 400GE-based networks in the coming years, network operators will achieve both lowest cost and highest performance only by drawing from a diverse and complete coherent product portfolio such as Nokia WaveFabric Elements.

The 400G era dawns with the alignment of these multiple innovations and technologies. 400GE will trigger a router investment cycle and spur demand for 400G wavelengths. Cost- and space-efficient 400G pluggable coherent transceivers will finally enable the physical integration of the IP and optical worlds, while the latest generation of high-performance coherent technology powers 400G transmission over any distance. This technological and temporal convergence is unique in the history of IP and optical networks and promises to make 400G the new universal network currency.

More to exploreSolution: Nokia WaveFabric

White paper: The 400GE inflection point






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Operators are confronting the Economic Shannon Limit and looking for more ways to get value from their optical networks. Investing in pluggable DCOs can help operators reduce cost and create exciting possibilities in the 400G era.

400G and the Economic Shannon Limit400G is poised to become the universal network currency for years to come, but it’s instructive to look back. A decade ago the iPhone was just taking off, and along with 4G mobile broadband it ushered in a new era of anytime, anywhere connectivity. In 2010 Netflix launched its streaming service internationally, a key step on its way to over 200 million subscribers. So it’s no surprise that bandwidth has continued to grow at roughly 30 percent per year. With the permanent changes in remote work and video conferencing we’re seeing as a result of COVID-19, this growth isn’t likely to slow down any time soon.

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The year 2010 also brought the introduction of two technology milestones: 100GE and coherent optical technology. Since then, continuous innovations in coherent technology have steadily increased the capacity of optical transport systems while pushing down the cost per bit transported. The result is that network operators have been able to accommodate the deluge of traffic while maintaining an effectively flat level of capital spend. This slow growth in CAPEX is critical to their ability to stay profitable in the face of stagnant subscriber revenue. As we enter the 400G era, the challenges for network operators are to continue to scale their networks, drive cost down and optimize transport around 400GE.

But there’s a problem. The rapid gains in capacity and cost reduction enabled by successive generations of coherent optics are largely behind us. Cost per bit reduction has been driven in large part by improvements in the spectral efficiency of coherent wavelengths. Shoving more bits into fewer interfaces and fewer fibers lowers costs.

The economics of 400G

Exponential traffic growth + rapid cost per bit reduction = slow CAPEX growth

2010

~30% annual traffic growth

Continual, rapid cost/bit reduction

Cost per bit

Traffic demands

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2020 2020






Yet spectral efficiency is famously bounded by the Shannon Limit. How close are we to this limit? Nobody knows for sure, but it is not far away. There are undoubtedly still some gains to be had but perhaps that’s not the question we should be asking. The more salient question might be this one: Does it make sense to continue to pursue gains in spectral efficiency, or would it be better to shift the focus of coherent research and development toward other methods of scale and cost containment? In other words, we may already have bumped up against what some call the Economic Shannon Limit.

The Economic Shannon LimitSimply put, the Economic Shannon Limit means that further efforts to maximize spectral efficiency are unlikely to generate a better return on investment (lower costs for operators) than exploring alternative technological avenues that lower costs by other metrics. Does our reckoning with the Shannon Limit mean that coherent innovation will come to a stop? Certainly not. But it does mean that the focus of investment and innovation will shift from squeezing more spectral efficiency out of a fiber – or the related metric of achieving higher wavelength rates — to technologies that optimize power and space to better match coherent interfaces to specific applications, as well as maximizing interface reach for workhorse speeds like 400G. And this is exactly what’s happening.

Each new generation of coherent technology has raised baud rates and lowered power per bit. Operation at higher baud rates increases the reach of a given wavelength rate. With spectral efficiency flatlining, this has become the primary benefit of new digital signal processor (DSP) generations. Lower power per bit is enabled by each new generations of silicon, which allows DSP engineers to cram more sophisticated signal processing and higher rates into the same power envelope.

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https://www.youtube.com/watch?v=HSoog0OqgV0&ab_channel=NokiaBellLabs

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Pushing the traditional, performance-optimized envelope of coherent optics are fifth-generation DSPs operating at 90+ gigabaud. These high-performance coherent interfaces use the most sophisticated digital signal processing algorithms such as second-generation probabilistic constellation shaping (PCS). and advanced optics to achieve robust, 400G-optimized wavelength performance across long-haul, ultra-long-haul and subsea networks that span many thousands of kilometers. This has allowed 400G over any distance, whereas two DSP generations ago, 400G wavelengths were limited to short metro spans of roughly 100 km or less. Nokia calls this 400G Anywhere, and our PSE-V Super Coherent (PSE-Vs) DSP is uniquely optimized around these demanding applications.

Fifth-generation digital coherent opticsAdvances in silicon can also be used to lower the absolute power of an interface from one coherent generation to the next. Both improvements reduce cost per bit, but the latter has given rise to smaller, more efficient pluggable coherent interfaces that are optimized for IP-optical integration, and network operators are already embracing them.

Nokia’s third- and fourth-generation DSPs featured a compact variant to complement high-performance super-coherent DSPs. These compact variants allowed optimization for power- and cost-sensitive applications that do not demand the highest spectral efficiency. Despite their lower power, these compact optical interfaces relied on board-mounted DSPs, most recently leveraging pluggable analog coherent optics, or ACOs, to house the optical

front-end (OFE) components. With fifth-generation optics, this trend advances further to include the widespread adoption of pluggable 400G DCOs, where the DSP and optical front-end components are tightly integrated and packaged together into a discrete module.

Pluggable DCOs packaged into standardized form factors such as QSFP-DD or CFP2 have the benefit of low power, small size and, most importantly, portability (or pluggability) into a wide range of platforms that utilize standardized input/output (I/O) ports, including routers, switches and optical transport systems.

But DCOs demand significant expertise, investment and coordination across multiple disciplines to meet performance requirements within the strict power and space envelopes of standardized module form factors. Future investment will concentrate on this tight integration of electronics and optics – DSPs and silicon photonics. This is the focus of Nokia’s WaveFabric Elements technology portfolio.

Evolution from discrete components to pluggable DCOs

Board-mounted DSP and OFE

Board-mounted DSP with pluggable ACO

Board-mounted DCO

Pluggable DCO

DSP OFE DSP OFEDSP OFE


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Operational benefits of pluggable DCOs for network operators Pluggable DCOs offer numerous advantages to network operators, including:

• Pay-as-you-grow interfaces: Coherent optics represent a significant portion of network spend. The ability to defer expenditures until demand arises helps network operators, particularly when deploying dense, multi-port line cards.

• Optics upgradeability: Optical and IP platforms can take advantage of improved performance, new features and possibly higher rates as DCOs rapidly mature throughout the lifespan of the line card or platform that supports them.

• IP-optical coherent integration: As they are implemented into common router pluggable optics form factors, DCOs will usher in a new era of IP-optical integration by eliminating the density penalty previously associated with router-based optics.

• Multi-vendor optics: DCOs open up the possibility of procuring coherent optics from vendors other than the platform provider, although there are significant technological and operational hurdles that must be overcome before this becomes widely feasible.

These application-, power- and density-optimized pluggable DCOs all have one thing in common – they are designed around 400G transport. As 400G will soon become the common currency of IP and optical networks, network operators will be able to choose among multiple interfaces to achieve the lowest cost per bit while simultaneously reaping the tremendous operational benefits that come with building an end-to-end 400G network across their IP and optical networks.

Pluggable DCOs aren’t just about cost reduction though. Their revolutionary power consumption, size and cost make possible applications that were previously ruled out as uneconomical or that were simply unfeasible because of power and space constraints.

Sometimes reaching a limit opens up new possibilities. While we’ve yet to hit the physical Shannon Limit, diminishing technological returns have forced us to confront the Economic Shannon Limit and to steer precious R&D resources in a different direction. But the goals are still the same – to continually lower cost per bit, and to help network operators not just stay afloat but to innovate as they transform their networks for the 400G era.

More to exploreTechnology: PSE Super Coherent Technology Ebook: Beyond the limit: Coherent solutions for the next decadeWhite paper: Nokia PSE-V coherent solutions beyond the limit

https://www.nokia.com/networks/technologies/photonic-service-engine/



Is your network ready for the transition to 400 Gigabit Ethernet? A new generation of pluggable coherent optics can help you optimize IP-optical network design.

Evolution of 400GE coherent opticsRelentless demand for more capacity at a lower cost per bit is forcing network providers to constantly rethink and reoptimize their network designs. Besides delivering more capacity for consumer internet and ultra-high-definition (UHD) video streaming services, they must provide high availability and low latency for the mission-critical and massive machine-type communication services that the cloud and 5G will enable. Rapid advances in silicon are fueling a new generation of compact, pluggable coherent 400G optics that open exciting new avenues for optimizing IP-optical network designs.

IP routing for the 400GE era

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Until recently, technology advances in coherent optics have focused on improving transmission performance with increasingly sophisticated DSP algorithms. Enormous progress has been made in this area, with probabilistic constellation shaping (PCS), introduced by Nokia in 2018, taking capacity close to Shannon’s limit to enable network operators extract maximum spectral efficiency from their networks. So where to next?

Improving optical transmission performance remains important for long-haul and subsea coherent transport applications, where fiber is expensive and scarce. But a new, complementary innovation focus has emerged, focused on improving the power, space and cost efficiency of coherent optics optimized for access, metro and regional reaches. The figure below shows the progress made in developing high-density optics, comparing progress in short-reach client optics for routers with that for pluggable coherent optics. Traditionally, there has been a sizable difference in the port densities of short-reach (gray) router optics and coherent line optics.

https://www.nokia.com/about-us/news/releases/2018/03/06/nokia-pushes-optical-network-capacity-to-theoretical-limits-with-photonic-service-engine-3-chipset-massive-scale-and-radical-simplicity-for-video-cloud-and-5g-growth/

Evolution of coherent optics

Client

SFP

SFP+

SFP28

QSFP28

QSFP56-DD

400ZR/ZR+

CFP2

CFPMSA Gen2

MSA Gen1

XFP

20000.1

1.0

10.0

100.0

Mbp

s/m

m3

2005 2010 2015 2020

Coherent






The introduction of 400ZR and 400ZR+ pluggable transceivers closes this gap and removes the I/O density penalty of using coherent optics in the same router ports designed for short-reach client optics.

The compact QSFP56-DD form factor offers tremendous port density but its power dissipation is nominally limited to 14.5 watts. However, coherent WDM transceiver designs are now pushing this up to 20 watts. This puts the onus on router engineering practices for efficient airflow and cooling to enable unconstrained use of coherent pluggable optics across a range of features and performance capabilities.

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400GE transceiver optionsNetwork operators need a range of 400G transceiver options to optimally address the different capacity, cost, topology and reach requirements in wide area networks. The table below lists the various options and their key characteristics.

400ZR was one of the first efforts to standardize an interoperable 400G coherent interface specification. Developed by the Optical Internetworking Forum (OIF) and released in March 2020, 400ZR is profile-optimized for high-density point-to-point access and data center interconnect (DCI) applications. It can deliver a single 400 Gb/s channel up to 40 km over a single dark fiber span without

external amplification and support up to 64-channel WDM in the C-band over a single span up to 120 km, with external amplification. Although 400ZR can be supported in various pluggable form factors, QSFP-DD is the most prevalent implementation choice.

In contrast, 400ZR+ is a related, non-standardized, extension of 400ZR that targets higher optical performance. It allows for multi-span transport using flexible 100G–400G line rates and longer reaches by leveraging multiple modulation types (16QAM, 8QAM and QPSK) and high-gain forward error correction (open FEC). In 400G mode, 400ZR+ can reach up to 600 km, and even further using subrates. It can also traverse a limited number of reconfigurable add-drop multiplexer (ROADM) nodes, albeit with reduced reach.

Technology 400ZR 400ZR+ 400G Multihaul 400G TransponderBit rate 400Gb/s only 100 – 400Gb/s 100 – 400Gb/s 100 – 800Gb/s

Reach 40 – 120 km (amp) 400 – 600 km (amp) 500 – 750 km (amp) >1,000 km (amp)

Modulation 16QAM QPSK, 8/16QAM QPSK, 8/16QAM QPSK, 8 – 64QAM

FEC CFEC CFEC+, oFEC CFEC+, oFEC, NOK FEC Proprietary

Tx power -7 to -10 dBm -7 to -10 dBm ~0 dBm >0 dBm

Form factor QSFP-DD QSFP-DD CFP2 Integrated line card

Interfaces 100GE, 400GE 100GE, 400GE 100GE/OTU4, 400GE 100GE/OTU4, 400GE

ROADM bypass No Limited Yes. Multiple Yes. Many

Application Metro DCI Metro Metro/regional Metro/regional Long haul/Subsea






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large installed base of QSFP-DD and CFP2-capable router ports that can be readily equipped to support 400GE, and by the many potential applications in DCI, metro access and aggregation rings, and metro/regional core networks.

Network operators need flexibility and choice in transceiver types to optimize cost and performance for a given (sub-)network or link because of dependencies relating to fiber availability, quality, reach, link topology and service requirements. IP-optical coordination is critical for seamlessly deploying, operating and assuring these options throughout the network.

Figure 2 depicts the transition to the 400GE era and the IP-optical interworking options that will enable this. The present mode of 100GE operation for most, if not all, operators is depicted on the left. It uses gray client optics in combination with optical transponders. The 100GE era started roughly ten years ago with the transition of IP backbone links to 100GE. It triggered a major upgrade cycle of core routing platforms. Today, 100GE is a ubiquitous interface in every part of the network, and 4x 100GE interface ports are a popular breakout option for QSFP-DD connectors.

When IP traffic scales to substantiate evolution of router ports to 400GE, plugging a coherent 400G transceiver into a router eliminates the need for an optical muxponder or transponder in the optical transport system. 400 Gb/s is ample bandwidth to

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400G Multihaul DCOs further expand on 400ZR+ capacity-reach performance using the CFP2 pluggable form factor that can be equipped in routers and/or WDM transponder systems. In addition, 400G Multihaul DCOs support 100–400 Gb/s line rates using QPSK, 8QAM and 16QAM modulation. They can also leverage higher launch power to achieve longer optical reaches up to 750 km and pass multiple ROADM hops.

400G pluggable DCO transceivers are complemented by the latest evolution in fifth-generation coherent optical transponders, which are performance-optimized to maximize wavelength capacity and reach. These transponders take the form of integrated line cards that reside within WDM optical transport systems. State-of-the-art optical transponders can deliver 400G services over thousands of kilometers by applying sophisticated DSP techniques and high-gain forward error correction (FEC). Optical transponders are typically deployed in combination with ROADMs for regional and long-haul networks where fiber connectivity is scarce and costly.

Transitioning to 400GEIt will take time to build an ecosystem for 400GE coherent pluggable optics, as with any new technology. Commercially available 400ZR, 400ZR+ and 400G Multihaul products will start shipping in mid-2021, and market uptake will be facilitated by the

IP Routing N x 100GE from router connect to transport layer via grey optics

Transponder or OTN switch mixes 100GE into WDM wavelengths

Coherent Transport

Optical line system provides ROADM-enabled wavelength switching and amplification

Optical Line System

The 100GE Era

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Pluggable 400G DCOs in routers enables IP-optical integration for access, metro and regional networks

Transponders/OTN For long spans or <400GE aggregation

Common ROADM-enabled optical line system for transponder/OTN and pluggable 400G DCOs

The 400GE EraTransition to the 400GE era






cost-efficiently fill a single wavelength but in many applications, router connections may need to accommodate prior generations of interface speeds, such as 100GE. Hybrid IP-optical solutions will continue to be used to efficiently meet variable capacity and reach objectives in mixed deployment scenarios that combine 100GE and 400GE interfaces or have link requirements that are beyond the reach of coherent pluggable transceivers.

Operators that are evolving their 100GE networks to 400GE are likely to operate in this mode for an interim period because it leverages their current optical network investments while offering incremental cost savings through the use of pluggable coherent 400GE transceivers. They may also still require present-mode solutions based on transponders on long fiber routes and for traversing larger numbers of ROADM hops in packet aggregation rings.

The 400GE era presents an opportunity for network operators to rethink and reoptimize IP-optical networks, and 400G coherent optical technology will play a key role in many future deployments. The choice of whether to evolve and optimize existing deployments or make a fresh start with next-generation solutions optimized for 400GE will largely depend on the age and longevity of each current network.

The Nokia IP-optical networking portfolio offers the scope, depth and range of 400G implementation options that operators need to make these decisions and succeed in the 400GE era. Nokia is a leader in 400G routing and optical technology and has achieved several industry firsts, including:

• Launching FP3, the first 400 Gb/s-capable routing silicon, in July 2011

• Demonstrating the first 400 Gb/s IP routing interfaces in February 2015

• Shipping the industry’s first commercially available 400GE line cards in July 2018

• Supplying the first commercial deployment of 400GE router interfaces in March 2019

More to exploreBlog: IP + optics: Better together in the 400G eraBlog: Better coordination of operations across IP and optical layers with SDNSolution: IP-optical coordination Technology: FP4 network processor

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Migrating IP-optical networks to 400G everywhere

The Nokia WaveFabric Elements optical portfolio expands the 400G ecosystem with new pluggable coherent transceivers and high-performance coherent subsystems designed to meet surging demands from 5G and the cloud. Launched in May 2020, it leverages a new generation of PSE-V coherent technology and integrated silicon photonics to power and push new benchmarks for transmission performance, cost efficiency and interface density.

https://www.lightwaveonline.com/network-design/high-speed-networks/article/16651735/alcatellucent-offers-400gbps-ip-router-interface

https://www.lightwaveonline.com/network-design/high-speed-networks/article/16651735/alcatellucent-offers-400gbps-ip-router-interface

https://www.de-cix.net/en/about-de-cix/media-center/press-releases/de-cix-first-internet-exchange-worldwide-to-offer-400-gigabit-ethernet-access-technology

https://www.nokia.com/blog/ip-optics-better-together-in-the-400g-era/

https://www.nokia.com/blog/better-coordination-of-operations-across-ip-optical-layers-with-sdn/

https://www.nokia.com/blog/better-coordination-of-operations-across-ip-optical-layers-with-sdn/

https://www.nokia.com/networks/solutions/ipoptical-coordination/

https://www.nokia.com/networks/technologies/fp4/

https://www.nokia.com/about-us/news/releases/2020/05/21/nokia-launches-new-wavefabric-elements-optical-portfolio-for-400g-ecosystem-to-meet-surging-demands-from-5g-and-cloud/

New 400GE standards and pluggable optics technologies are bringing true IP-optical integration within reach. What are the use cases and what ingredients are needed to enable 400G anywhere?

Use cases and building blocksNew developments in IP and optics are re-igniting discussion about IP-optical integration. Standardization of the 400GE protocol is leading the industry to embrace 400G as the new currency for high-bandwidth router connections. Router ports designed to accept 400G pluggable optics can now also be equipped with pluggable WDM coherent transceivers. These transceivers extend high-speed connections to much longer distances across the WAN and allow network operators to forgo the use of transponders implemented in a separate WDM transport system.

400G IP-optical solutions

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All of this leads to two key questions. What are the use cases for IP-optical integration? And what IP and optical elements are required to enable an end-to-end solution that is more than the sum of its parts?

There are as many network types as there are network operators, but we can narrow these down to a few typical cases that vary based on the increasing complexity of their service connections and network scope, as shown in the figure below. The first category covers applications that require simple point-to-point connection of multiple 400GE ports between routers. It includes campus networks, high-bandwidth access links and metro DCI, and may extend to longer distances for regional DCI to enable data center virtualization. In such cases, the requirement for an IP-optical solution mainly calls for simple WDM aggregation of multiple 400G interfaces, and optical amplification whenever the link distance exceeds a few tens of kilometers .

In more complex network topologies, IP traffic doesn’t simply start and end at each routing node. It consists of complex, meshed, end-to-end service demands that generate high volumes of through traffic. Effective IP-optical network solutions should offer a range of connectivity and distance options that cost-effectively support the ability to add and drop services to and from multiple destinations, and support pass-through traffic that needs to transit intermediate nodes. It should provide these capabilities with minimal interface transitions between IP routing and optical transport layers. To achieve this, network operators need to consider four key IP-optical building blocks necessary for providing optimal and versatile solutions across the full range of 400G network applications:

1. Pluggable coherent WDM optics in different form factors to meet cost and connectivity objectives

2. Suitable IP routers that are designed to support these pluggable coherent optics

3. Optical line systems that efficiently connect routers and multiplex wavelengths on fiber links

4. Multilayer IP-optical management and control software that supports seamless, end-to-end operation






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Optimal IP-optical solutions should enable use across a wide range of network types

Access & Metro DCISimple

Point-PointNo add/drop

10s – 100s km

Metro AggregationMedium

Rings 2-4 way add/drop

10s – 100s km

Metro & RegionalComplex

Rings & Mesh Multi-degree add/drop

100s km

Long-HaulComplex

Mesh Multi-degree add/drop

100s – 1000s km

Besides linear, point-to-point applications, viable IP-optical solutions must also accommodate a wide range of more complex network use cases. These include:

• Metro and regional aggregation rings that collect hub and spoke traffic from access nodes and central offices to one or more service hubs

• Metro core networks with any-to-any traffic connections between central offices (COs), internet exchanges (IXs) and co-location sites

• Regional and long-haul core backbones that interconnect cities and regions, along with widely disparate DCs and internet peering sites

Router-pluggable coherent opticsPluggable DCO transceivers can be equipped directly in router ports to provide the scalable WDM capacity required to link high-capacity routers. These transceivers support a range of options:

• 400ZR is designed for short-reach links up to 120 km.

• 400ZR+ adds multi-rate capability and extends reach.

• 400G Multihaul transceivers further expand capacity–reach capability, add service provider-oriented features and support pass-through traffic for multiple nodes using ROADMs.

The incremental capability of 400G Multihaul DCO transceivers makes them an important element in a portfolio of IP-optical solutions. Their longer reach extends the application space of IP-optical applications into metro and regional networks and across longer distances. It also enables optimized router bypass through intermediate nodes, allowing end-to-end traffic demands to avoid unnecessary router transits.






A complete set of optimized IP-optical solutions enables more than the sum of its parts

Management & control• Multilayer• Multivendor• Automation

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IP Routing• Scalable• Multiservice• High density

Coherent optics

• Capacity• Reach• Flexibility

Optical line system

• Pluggable• 400G• Reach options

Optimized routers for IP-optical integrationRouting platforms are judged across a wide range of attributes unrelated to optics. However, the ability of routers to successfully integrate pluggable 400G DCO transceivers is a critical part of any successful IP-optical solution. Nokia’s market-leading service routers, based on the FP4 family of scalable, programmable packet processors, are notable for having enabled the first commercial deployment of 400GE interfaces. They have been engineered with IP-optical integration in mind. Their design addresses two important requirements for successfully integrating 400G DCO transceivers: thermal management and interface diversity.

Power consumption and heat dissipation are higher for 400G pluggable coherent optics than for short-reach client optics. Power and cooling of line card cages can become an issue for routers designed to maximize switching capacity and interface density. The thermal design of 400G-capable line cards is thus a critical element for coherent IP-optical integration. It determines a router’s ability to efficiently cool all interface ports, including pluggable 400G coherent optics.






Nokia’s router design practices prioritize efficient thermal management with features such as dual-sided line card printed circuit boards (PCBs) to avoid stacked optics cages, a large dedicated heatsink for each cage to improve cooling, and air guides to ensure even and unobstructed airflow. This combination of features means that Nokia routers can accept the complete range of pluggable 400G DCO transceivers without limitations such as dedicated slots, equipping rules or leaving some ports empty.

Routers need to support the full range of 400G pluggable form factors to enable IP-optical solutions across all network use cases. While 400ZR and 400ZR+ in QSFP-DD formats can be equipped in the same router ports as short-reach client optics, their capacity–reach performance limits their use to short- or medium-reach point-to-point links for access and metro DCI applications.

Nokia routers also support interface cards with CFP2 ports. This enables operators to use pluggable 400G Multihaul optics to provide superior capacity–reach performance for metro and regional applications, and to transit multi-node links with ROADMs at intermediate sites.

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A complete range of 400G coherent optics in routers and transponders enables 400G everywhere

Access and Metro DCI

Metro Aggregation

Metro Core and Regional

High-performance Core/Long-Haul

400ZR 400ZR+ 400G Multi-haul

400G Transponder

Transponder based coherent optics

Router based coherent optics

In addition, Nokia routers enable operators to interwork router-pluggable coherent optics with transponder-based optics over common network links to allow further optimization based on end-to-end service demands. By providing the ability to mix and match coherent interface options with different form factors, Nokia platforms enable operators to make optimal use of 400G as a single network currency across all network applications.

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Application-optimized optical line systemsThe next consideration is how to best interconnect routers with 400G coherent optics over a fiber network. Efficiently connecting routers over fiber is the task of the optical line system, which implements a collection of important functions, including:

• Multiplexing/de-multiplexing multiple WDM channels onto a fiber

• Optical amplification at endpoints and intermediate sites to boost optical power levels for greater reach

• ROADMs that can route and switch 400G coherent links as needed to optically bypass intermediate router nodes and avoid the unnecessary consumption of router capacity for transit traffic

The Nokia 1830 PSS family provides a full range of line system options to enable optimal configurations for all IP-optical network use cases. Targeted features such as WDM mux/demux and amplifiers can provide operators with a compact and cost-efficient solution for DCI and other simple point-to-point applications. For more complex networks, operators can add features such as ROADMs to enable optical bypass in metro aggregation rings, or for multi-degree nodes with a large number of ingress/egress directions. The 1830 PSS also enables operators to optically bypass intermediate router nodes where and when needed.






This makes it easier to reengineer and optimize IP-optical links to efficiently accommodate network growth, changing demand patterns, and planned or unplanned network outages.

The key to tying routers, pluggable coherent optics and line systems together to create a deployable IP-optical solution is to integrate them into a unified end-to-end network management, control and automation platform.

More to exploreBlog: Optimizing open line systems to support 400G anywhereBlog: How to boost the efficiency of your operations with automation across IP and optical layersSolution: Network Services PlatformApplication note: Achieving efficient IP-optical network automation with the Nokia NSPSolution: Wavelength routingBrochure: Nokia WaveFabric advanced wavelength routing

IP-optical managementTo create 400G IP-optical solutions that are more than the sum of their parts, operators need a complete set of hardware and software building blocks optimized around the new network currency of 400G. These solutions should include a range of pluggable coherent optics, routing platforms optimized for 400G coherent pluggable transceivers, multifunction optical line systems, and multilayer, end-to-end management.

When combined and deployed in synergy, these building blocks give network operators flexible options for addressing a wide range of network use cases without making trade-offs in cost or performance. This helps operators avoid the need to over-design IP-optical solutions for short, point-to-point access and metro links, or to overspend on inefficient architectures or underperforming optics in more complex metro, regional and core networks. With the ability to choose and combine the right options in each instance, and evolve, expand and upgrade when needed, operators can ensure that they will realize the expected benefits of IP-optical integration.






22 © Nokia 2021

https://www.nokia.com/blog/optimizing-open-line-systems-to-support-400g-anywhere/

https://www.nokia.com/blog/how-to-boost-the-efficiency-of-your-operations-with-automation-across-ip-and-optical-layers/

https://www.nokia.com/blog/how-to-boost-the-efficiency-of-your-operations-with-automation-across-ip-and-optical-layers/

https://www.nokia.com/networks/solutions/network-services-platform/



https://www.nokia.com/networks/solutions/wavelength-routing/#overview


A 400G and optical technology leaderPluggable 400G DCO technology is a game changer for optimizing IP-optical network designs for the 400G era. These compact and modular 400GE transceivers offer a low-cost, high-density alternative to conventional solutions by using gray router optics with integrated WDM transponders in optical line systems.Our IP routing and optical systems portfolio offers the scope, depth, platforms and tools you need to capitalize on pluggable DCOs and succeed in the 400G era. The innovative power and cooling designs of our QSFP56-DD and CFP2 line cards make it easy to equip 400GE coherent pluggable transceivers in existing Nokia routers and line cards.

We also lead the way in coherent optical components and line systems. The combination of our state-of-the-art silicon photonics and fifth-generation PSE-V digital signal processor will take transmission performance, cost-efficiency and interface density to new levels. Our WaveFabric Elements optical portfolio expands the 400G ecosystem with new components and subsystems to meet surging demands from 5G and the cloud.

For more on this visit our webpage, nokia.com400Geverywhere

23 © Nokia 2021






Nokia OYJKarakaari 7 02610 EspooFinland

Document code: (May 2021) CID210434

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