a comprehensive approach to multi-layer transport network automation

8/10/2019 A Comprehensive Approach to Multi-layer Transport Network Automation

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A ComprehensiveApproach to Multi-layer

Transport NetworkAutomationService providers continue to face staggeringincreases in bandwidth, driven primarily by videoand cloud combined with increasingly competitivebroadband and mobile access speeds. This growth

requires ongoing CapEx investment in the networkat both the IP/MPLS layer (Layer 3/2.5) and the OTNand DWDM transport layer (Layer 1/0) so that serviceproviders can continue to deliver high quality networkexperiences to their customers. Wall Street, on theother hand, continues to demand strong financialperformance with new revenues and flat or decliningCapEx-to-revenue and OpEx-to-revenue ratios.

WHITE PAPER


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This tension results in a need for service providers to break away from the status quo and evolvetheir network architectures so that they can scale while simultaneously creating new revenuesources and driving cost efficiencies. In 2013 Infinera unveiled the Intelligent Transport Network,which was built to help service providers with this challenge, enabling them to:

Massively scale networksbased on photonic integration, featuring platforms and anarchitecture that is designed for 100G and 500G DWDM super-channels today andterabit+ DWDM super-channels in the future.

Converge multiple layers of the network,such as DWDM and OTN switching, to furtherreduce both CapEx and OpEx costs (power, space, fiber patches, maintenance, etc.).

Automate the network with GMPLS and SDNto support rapid service delivery, resultingin a more competitive market posture for increased revenues complemented by singlescreen automation to reduce operational costs.

The Intelligent Transport Network architecture allows network scale that not only supplies a moreefficient transport layer but also leverages convergence and intelligence to make the IP/MPLSlayer and thus the network as a whole more efficient by reducing the number of router resources

needed to deliver a certain set of service demands.

FIGURE 1: ITN Architecture Diagram

EVOLVING TO THE TERABIT ERA

INTELLIGENTTRANSPORT NETWORK

ATNDTN-X

DTN

PIC

10G100G 100G 500G Terabit

2003 2007 2013 2020

Converged OTN Switchingand WDM

Without compromise

PhotonicIntegratedCircuit (PIC)

An industry first

VisionAn Infinite Pool

of IntelligentBandwidth

AutomationOpen Software Control

ConvergenceMulti-layer Switching

ScalabilitySuper-channel Transmission

DIGITAL OPTICALNETWORK


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Intelligent Transport Network Evolution

This architecture has seen wide adoption across the globe and is now evolving to extendthe highly regarded ease of use of the Intelligent Transport Network into a dynamicallyreconfigurable flexible grid optical layer. Three key enhancements have been added:

Infineras third generation, 500G super-channel line cards have been introduced tosupport flexible grid operation. The scalable optical layer has now evolved from fixed gridto flexible grid to reflect the latest developments in the ITU-T DWDM standards.

A super-channel colorless, directionless, contentionless (CDC) FlexROADM has beenincorporated to create a uniquely powerful multi-layer switching capability as anenhancement to, and working in concert with, Infineras existing non-blocking OTNswitching capability.

The resulting flexible multi-layer digital and optical network is automated with a unified,carrier-grade control plane that represents the first production implementation of theSpectrum Switched Optical Network (SSON) extensions to GMPLS.

This ongoing evolution has always been a part of Infineras vision for Intelligent Transport; andit benefits from the ability to work from a clean slate designdelivering a solution withoutcompromises (no retrofits) in terms of scale, converged multi-layer switching, and end-to-endautomation.

While the flexible grid super-channel layer delivers vital additional capacity, this paper willfocus on two specific capabilities of this architecture: converged multi-layer switching andunified automation.

Converged Switching: Phase 1

Chronologically, the first phase of this convergence was the introduction of a high-capacity (multi-

terabit), non-blocking OTN switch with the ability to switch up to 10 Tb/s in a single bay and 240Tb/s in a multi-bay configuration. There were two major factors that enabled Infinera to deliverthis convergence without compromise:

Large scale photonic integrated circuits (PICs) provide massive amounts of DWDMcapacity in a small power and space envelope as well as the headroom to integrate theelectronic switching functionality.

A system was designed from the ground up for this convergence (using custom-designedASICs) versus a retrofit approach, seen with many other solutions on the market.

This timing of this first phase was vital because the switch was purpose-built to groom largenumbers of lower data rate services, such as 1 GbE and 10GbE, into coherent DWDM super-channels of 500 Gb/s and beyond. A key aspect of network planning is that there is no point in

optically switching 100G or 500G super-channels if they are not efficiently filled.

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This means that each slot must be capable of providing 500 Gb/s access to the switch fabric. Infact, Infinera has designed the system with a backplane capacity that supports over 1 Tb/s perslot to support terabit+ super-channels in the future, potentially delivering long term investmentprotection.

In addition, service providers can use advanced OTN switching functionality to leverage InfinerasFast Shared Mesh Protection (FastSMP) to provide per-service granularity for sub-50msservice protection with excellent levels of bandwidth efficiency. FastSMP, featuring the FastSMPProcessor, is the industrys only hardware accelerated shared mesh protection solution.

Converged Switching: Phase 2

Once the long-haul, coherent super-channels are efficiently filled via OTN switching andgrooming, service providers need a way to manage this bulk capacity at the lowest possiblecost, and to be able to shift it around the network as demand dictates. This is where Infinerasup to nine degree super-channel CDC FlexROADM shines as a complementary tool. The OTN

function fills the super-channels, and then, when needed, the ROADM can optically express thesefilled super-channels to lower network costs or to reroute the super-channels to meet changingnetwork demands.

ROADM technology is not new, but until recently ROADMs were based on fixed grid technologythat cannot support flexible multi-carrier super-channel capacity. A FlexROADM is designed tooperate on the new ITU-T G.694.1 Flexible Grid, using a building block granularity of 12.5GHz which is ideal for the efficient support of coherent super-channels. Infineras super-channel CDCFlexROADM is available in a modular format that can be used to construct any configuration ofbasic, C, CD, and CDC FlexROADMs with up to nine degrees.

OTN SWITCHING

MULTI-LAYER

SWITCHING

OPTICAL

Comprehensive tool Kit

Fill super-channels with OTNmux/switching

Route optically to reduceregens & planning

All remotely configured withpoint-click GMPLS/SSONcontrol plan

Maximum efficiency ANDflexibility to remotelyredeploy BW & new services

Point and click ODU0/flexswitching granularity

Digital grooming maximizesWDM fill->CapEx savings

Sub-switching & FastSMPprotection -> OpEx savings

Wavelength & super-channelgranularity

Optical express of filledsuper-channels -> CapEx savings

Reconfigurable super-channelswitching -> OpEx Savings

Unified

Control

Plane

Figure 2:DTN-X Multi-Layer Switch Diagram


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A CDC ROADM is designed to dramatically reduce the need for rigorous offline planningbecause it can be reconfigured at any time without any blocking conditions while allowingwavelength or super-channel switching operations to take place in a highly deterministic fashion.The end result is that service providers can make changes to the fundamental optical routing oftraffic in the network remotely, and avoid expensive truck rolls.

The Best of Both Worlds

As Figure 2 shows, by combining a high capacity, non-blocking OTN switch with a super-channelCDC FlexROADM, service providers can have the best of both worlds. Table 1 summarizes theindividual use cases for one technology or the other, but the fact that both of these functions areco-located in the DTN-X node means that the network designer has the best of both worlds.

A Unified Layer GMPLS/SSON Control Plane

So, to realize the full value of the flexible digital and optical switching functions (data plane) itsessential to develop a unified control plane so that these no-compromise switching tools canhelp automate day-to-day network operations. Generalized MPLS was designed to be able tocontrol practically any underlying data planeincluding packet, frame, TDM and wavelengthtechnologies. Infineras existing and highly successful GMPLS control plane has been widelydeployed for OTN operation in accordance with the GMPLS Framework. The SSON extensionsallow GMPLS to extend its capabilities to a flexible grid super-channel data plane, thus creatingan industry-leading unified control plane.

Requirement OTN Switching Optical Switching

Bandwidth granularity Point and click provisioning

and ODU0/flex switchinggranularity

Wavelength and super-

channel granularity for bulktraffic management

CapEx saving CapEx saving achieved bysub-super-channel servicegrooming for efficient fill

CapEx saving achieved byoptical express of alreadyefficiently filled super-channels

Restoration strategy FastSMP sub-50ms protectionat service level granularity

Optical restoration (severalseconds) at the wavelength,super-channel or fiber level

Table 1:Service Requirements vs. Switching Architecture


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Figure 3 shows the elements of Infineras unified control plane, and how this has been extendedfrom the digital switched domain to encompass the new flexible optical layer:

ADAPT is Infineras amplifier automation protocol. Combined with coherent super-channels, ADAPT allows hands-free turn-up of super-channel capacity.

GMPLS technology provides a unique topology discovery and automated inventory

management capability, which can now be extended into the flexible optically switcheddomain.

In the Internet Engineering Task Force, Infinera is helping to drive the architecture andprotocol extensions to GMPLS that allow Spectrum Switched Optical Networks to operatein concert with the digital switching domain.

In terms of restoration strategies we can augment the sub-50ms FastSMP protectioncapability in the digital domain with GMPLS/SSON-driven optical restoration.

This final point is very much at the leading edge of control plane technology. Flexible spectrumsuper-channel networksor Switched Spectrum Optical Networks (SSON), as they are knownhave not historically been covered by the GMPLS framework. The Common Control andManagement Protocol (CCAMP) Working Group within the Internet Engineering Task Forcehas proposed to extend the GMPLS Framework (followed by protocol extensions to OSPF-TE

Network Failure

Hello Hello

ADAPTAutomatic adjustment & monitoring of

WDM parametersHands-free link turn-up & optimization

AUTO-DISCOVERYTopology DiscoveryInventory and Configuration

Management

GMPLS/SSONRoute ComputationPoint and Click Provisioning

RESTORATION


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and RSVP-TE) so that super-channels, and FlexROADM technology, can be managed under theGMPLS/SSON umbrella.

This unified control plane is designed to use every wavelength efficiently, provide the abilityto remotely route super-channels on demand, and provide a powerful set of tools to maximizenetwork efficiency and flexibility to lower both CapEx and OpEx while simultaneously scalingthe network.

Summary

Infineras Intelligent Transport Network has been designed from a clean slate to deliver scale,convergence and automation without compromise. The combination of coherent long haulsuper-channels, non-blocking OTN switching, and a GMPLS control plane is already leading theindustry in terms of delivering highly automated transport network capacity for service providersaround the world. This important enhancement to the Intelligent Transport Network architectureto support flexible grid operations, and to extend network flexibility into the optical domain

with full automation, will ultimately allow service providers to address their key challenges ofmaximizing network capacity and rapidly deploying new services while reducing capital andoperational costs.


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Infinera Corporation140 Caspian CourtSunnyvale, CA 94089 USATelephone: +1 408 572 5200Fax: +1 408 572 5454www.infinera.com

Have a question about Infineras products or services?Please contact us via the email addresses below.

Americas: [email protected] & Pacific Rim: [email protected], Middle East,and Africa: [email protected] E-Mail: [email protected]

www.infinera.com

Specifications subject to change without notice.

Document Number: WP-AE-3-2014 Copyright 2014 Infinera Corporation. All rights reserved.Infinera, Infinera DTN, IQ, Bandwidth Virtualization, Digital Virtual ConcatenationandInfinera Digital Optical Networkare trademarks of Infinera Corporation

a comprehensive approach to multi-layer transport network automation

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