Alcatel June 2011 Entering the Terabit Era en StraWhitePaper

7/29/2019 Alcatel June 2011 Entering the Terabit Era en StraWhitePaper

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S T R A T E G I C W H I T E P A P E R

Explosive bandwidth demand and rising consumer expectations or rapid access to servic-

es constitute the exafood phenomenon a stressor on network inrastructures and on

service providers budgets that demands huge capital investments and ultimately results

in higher operating costs. Todays service providers are seeking a way o reducing the cost

o transporting high volumes o trac while extracting value rom innovative services.

The next-generation Optical Transport Network (OTN) inrastructure supports emerg-ing ultra-high rate services. A converged ramework that uses photonic and electronic

networking, OTN integrates Dense Wavelength Division Multiplexing (DWDM), Recon-

gurable Optical Add-Drop Multiplexer (ROADM) networking, and Optical Transport

Hierarchy (OTH) sub-wavelength circuit networking. OTN provides a consistent, scalable,

reliable, dynamically congurable optical layer that is cost-eective and responsive to

ever-growing, unpredictable IP trac demands. This paper explores the oundations

o OTN, introduces the advantages o a converged OTN/WDM platorm and describes

its benets as a key building block o the Alcatel-Lucent High Leverage Network

Converged Backbone Transormation (CBT) Solution, enabling scalable and ecient

IP bandwidth management at the lowest cost per transported bit.

Entering the Terabit Era

Implementing the intelligent Optical Transport Network to facethe exaood phenomenon and support sustainable IP trafc growth


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Table of contents

1 1. The exaood phenomenon

1 2. Converged backbone transformation: seamless IP-optical integration

2 3. Rethinking network architecture

2 3.1 Drivers of a next-generation backbone network

4 4. Building OTN on a proven foundation

6 4.1 OTN hierarchy

7 5. Efciently scaling the IP backbone

7 5.1 Opportunities for greater efciency

9 5.2 Beyond IPoWDM: efcient IP trafc grooming options

11 5.3 Optimal lling of network resources

12 5.4 Service differentiation

12 6. Taking quality assurance and operational simplicity to the next level

12 6.1 Enabling transparent capacity services for the carriers carrier

13 6.2 Enhancing quality control in a multicarrier environment

14 6.3 Decreasing network recovery time

14 6.4 Control plane intelligence for enhanced reliability and operations

15 6.5 IP and optical cross-layer control plane

15 7. Entering the terabit era with the Alcatel-Lucent 1830 PSS

16 7.1 Alcatel-Lucent 1830 PSS-64 and 1830 PSS-3617 7.2 Economically viable 100G deployments

17 8. Conclusion

18 9. Acronyms


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Enter ing the Terabit Era | Strategic White Paper 1

1. The exaood phenomenon

Initially, a 50 percent annual increase in Internet trafc might seem to be a boon to service provid-ers, especially when combined with dramatic growth in multimedia applications and business andconsumer IP services. The continued explosion in bandwidth demand, accompanied by consumerexpectations o aster access to services, is reerred to as the exaood phenomenon. This situationputs tremendous stress on the existing network inrastructure, orcing service providers to invest

heavily in expansion. However, more inrastructure invariably means higher operating costs, creat-ing an apparently irreversible upward spiral.

The overall capacity o transport networks is being increased, with line rates moving rom 10 Gb/sto 40 Gb/s and 100 Gb/s.

In contrast, the revenues associated with new IP services are not increasing at the same rate as theboom in trafc, decreasing service providers ratios o revenue per transported bit. Service provid-ers are aced with a momentous challenge as they seek new ways to support the cost-power-capacitycrunch by lowering the cost per transported bit.

2. Converged backbone transformation: seamless IP-optical integration

Service providers must meet the challenge o reducing the cost o transporting high volumes o tra-fc while simultaneously extracting value rom innovative services. A new architectural approach isneeded one that optimally combines optical transport and routing technologies to achieve scal-able and cost-eective IP transport or any new service demand. This is the essence o the Alcatel-Lucent High Leverage Network Converged Backbone Transormation (CBT) Solution, in which thenext-generation Optical Transport Network (OTN) inrastructure plays a key role (see Figure 1).

Designed to exibly support high rate services rom 1 Gb/s to 100 Gb/s and beyond, OTN andIP-over-OTN solutions provide a dynamically confgurable optical layer that is responsive to IPnetworking demands. These solutions also enable multilayer optimization with superior serviceresiliency. With an OTN architecture in place, service providers can scale their IP backbone inra-structures and respond to huge trafc demands without incurring the extra costs associated with

expensive routing capacity upgrades.

Alcatel-Lucent inuses OTN with additional intelligence or a solution that enables efcientbandwidth management at the lowest cost per bit.

Figure 1. Alcatel-Lucent CBT Solution

Contentdelivery

Service routers

Internet peering

Control plane integration Increased cross-layer visibility

and resiliency, with improvedresource efficiency

Management plane integration Seamless network visibility, provisioning and

troubleshooting across IP and optical domains

Data plane integration 10/40/100G on optics and IP Flexible grooming and IP shortcut

options to maximize link utilization

Service router Service router

Data centers

Converged service-awarenetwork managementTransformation services

Converged backboneAggregation/edge

Service routers OTN/photonic switches

OTN/photonic switch

OTN/photonic switch

IP opticalintegration

Corerouters


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Entering the Terabit Era | Strategic White Paper2

Integral to the Alcatel-Lucent CBT Solution is the Alcatel-Lucent 1830 Photonic Service Switch(PSS), eaturing a new class o optical-core switching platorm with terabit capacity and OTN sup-port in addition to best-in-class Wavelength Division Multiplexing (WDM) unctionalities.

New challenges require new approaches, and Alcatel-Lucent is committed to ully exploring innova-tive core-network transormation solutions that will help dramatically improve efciency by trans-porting at the lowest cost per bit.

3. Rethinking network architecture

Todays backbone transport networks are typically based on a WDM layer that provides raw point-to-point capacity with 2.5 Gb/s, 10 Gb/s or 40 Gb/s line rates over long distances. Optical cross-con-nects in meshed topologies provide reliable SDH/SONET networking or managing bandwidth atthe sub-wavelength level. These cross-connects create an intelligent, exible transport network layerwith highly efcient bandwidth management capabilities. Trafc ows between dierent networklocations can be managed optimally and simply, with reliability and high quality, enabling efcientlevels o connectivity in the IP backbone inrastructure.

A key challenge or these networks, as previously indicated, is scalability. As Internet trafc

increases with the growth o high-bandwidth applications, transport line rates increase rom10 Gb/s to 40 Gb/s and 100 Gb/s. While these rates clearly exceed the scalability o SDH/SONETas a sub-wavelength transport layer, the strain on the IP layer also grows: in the absence o a sub-wavelength transport layer, nearly all transit trafc crosses routers that directly interconnect to theWDM layer or raw wavelength capacity.

A new way o thinking about network architecture is needed. The most efcient solution is one thatoers an optimal combination o optical transport and routing technologies, capable o transport-ing IP trafc at the most economical layer. The solution must be scalable and capable o leveragingsub-wavelength and wavelength layers within the OTN in line with the service mix and trafcdistribution.

3.1 Drivers of a next-generation backbone network

Service providers costs are growing proportionally with trafc but are misaligned with revenuegrowth and proftability. To compete, they must:

Solve the cost-capacity challenge

Maximize bandwidth monetization

Ensure high availability and quality assurance

Simpliy operations and reduce total cost o ownership (TCO)

3.1.1 Solving the cost-capacity challenge by efciently scaling the IP core

Service providers can support trafc growth while controlling costs using a highly efcient back-

bone network architecture, optimally combining transport and routing capabilities to manage trafcexplosion at the most economical layer.


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The architecture can leverage an OTN inrastructure that provides the most efcient sub-wave-length bandwidth management capabilities or trafc up to 40 Gb/s and 100 Gb/s, scales to multi-terabit capacity. The OTN inrastructure can optimize the transport o router trafc using multipleorwarding options (at the wavelength and sub-wavelength levels) according to service mix andtrafc destination. As shown in Figure 2, trafc can be ooaded rom core routers onto the opticallayer, thereore expanding overall network efciency and lie cycle, while trafc ows can be indi-vidually managed or quality assurance and optimization o overall network utilization, perormance

and cost.

Figure 2. Optimizing IP transport with the Alcatel-Lucent CBT Solution

Serviceedge (PE)

Status quo: rout ng tra c troug core P routers

Corerouter (P)

Corerouter (P)

Corerouter (P)

Serviceedge (PE)

DWDMMux

DWDMMux

DWDMMux

DWDMMux

DWDMMux

Serviceedge (PE)

CBT with IP shortcut: Bypassing core P routers

P = Provider, PE = Provider edge

Corerouter (P)

Corerouter (P)

Corerouter (P)

Serviceedge (PE)

DWDM/OTNswitch

DWDM/OTNswitch

DWDM/OTNswitch

DWDM/OTNswitch

DWDM/OTNswitch

This approach oers maximum granularity by enabling multiple trafc grooming options or thelowest cost per transported bit, eliminating unnecessary transit trafc in the IP layer and optimizingport efciency. OTN integrates sub-wavelength and wavelength layers, enabling a highly scalablebackbone inrastructure. With OTN, efcient IP trafc grooming options can be optimally andeconomically perormed in the transport layer, avoiding overloading o the IP routing platorms.

3.1.2 Maximizing bandwidth monetization

Revenues per transported bit can be improved in an OTN with advanced automation and intelli-gence. Highly sophisticated restoration algorithms that make use o a standard Generalized Multi-Protocol Label Switching (GMPLS) control plane can minimize the number o wavelength andsub-wavelength bandwidth resources in the network that must be allocated or service resilience.This maximizes the reuse o available transport resources and rees network capacity or new,paying trafc.


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3.1.3 Ensuring high availability and quality assurance

In an OTN, advanced control plane-based network protection and restoration capabilities enableService Level Agreement (SLA) assurance and high availability. Consolidated transport-gradeoperations, administration and maintenance (OA&M) monitoring and ault management toolsextend to new, higher bit rates. End-to-end SLA assurance and ault sectionalization capabilities areenhanced or multicarrier/multidomain networking scenarios.

3.1.4 Simpliying operations and reducing TCOThe OTN provides a range o operational benefts to service providers:

Leverages intelligence and automation to optimize network operations across the optical and IPlayers and accelerate time to service

Reduces overhead costs by managing trafc efciently and with maximum scalability

Relies on consolidated transport network operational models to reuse existing operational skills

Minimizes the number o transport entities necessary or each transported service

Eases the pressures and costs associated with maintaining an always-on network by minimizingthe need or on-site interventions during ailures

Utilizes the network optimally, ensuring maximum power efciency by provisioning services

automatically across the most economical resources in the network

4. Building OTN on a proven foundation

Operators have become highly dependent on and attached to the strengths o the previ-ous transport network solutions deployed almost universally over the past two decades. Customersneed proven transport unctionalities such as deterministic perormance, comprehensive OA&Mtools, efcient grooming o multiple trafc ows, trafc monitoring, quality measurement and aultlocalization, and resilience against ailures. These are all key elements o a reliable, easy-to-operatetransport network inrastructure.

Standardized by the ITU-T, OTN capitalizes on past transport experience and extends capabilities

to higher bit rates and multicarrier domains. OTN integrates these capabilities with WDM net-working unctions in a single consistent ramework to provide a high-capacity oundation or next-generation OTNs. In essence, OTN builds on the graceul mix o photonic and electronic switchingcapabilities, which play complementary roles or maximum network efciency:

Photonic switching domain Optical signals transiting a network node are switched at thewavelength level. This is best suited or cases in which the granularity o the transported serviceis close to the wavelength capacity. Photonic switching is used primarily to provision and restorewavelength services.

Electronic switching domain Each optical signal is terminated, and the entire signal or itsservice-specifc trafc contributions can be individually switched. Electronic switching is usedprimarily to provision and restore sub-wavelength services that consume less than a wavelength

o bandwidth.

OTN networking oers ull management capabilities or the wavelength layer by introducing theOptical Channel (OCh). OTN integrates a new, expanded hierarchy or sub-wavelength bandwidthmanagement: the Optical Transport Hierarchy (OTH), which oers a powerul networking toolcapable o managing 1 Gb/s, 2.5 Gb/s, 10 Gb/s, 40 Gb/s and 100 Gb/s bandwidth pipes, includingincrements o multiple 1 Gb/s or maximum exibility.


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By combining photonic- and optoelectronic-based bandwidth management eatures and associatedoperational tools, OTN enables transparent transport or virtually any trafc type and rate across ascalable, reliable optical networking inrastructure, ensuring deterministic quality assurance.

With worldwide trafc rates set to jump each year, the ability to simply and efciently manageever-increasing trafc volumes is o huge beneft to operators. In this respect, OTN meets data-driven bandwidth needs and supports the emergence o new broadband services. Its multiservice-

capable core inrastructure is based on lessons learned rom SDH/SONET, incorporating additionalhigh-bandwidth optical technology to meet the challenges o the telecommunications networkingenvironment evolving toward ull IP. OTN provides the gigabit-level bandwidth granularity requiredto scale and manage multi-terabit networks and oers service providers the tools or simpliyingoperations and improving network efciency as trafc increases. OTN:

Maximizes nodal switching capacity to the multi-terabit level, the gating actor or reconfgu-rable network capacity

Minimizes the need or large numbers o fne-granularity pipes that complicate network plan-ning, administration, survivability, management systems and control protocols

Enables end-to-end quality assurance o client services while decoupling transport granularityrom DWDM line system capacity

Enhances SLA verifcation capabilities in support o multicarrier, multiservice environments

At the heart o OTN, OTH is a bandwidth management hierarchy in the electronic domain orvery high rate signals up to 100 Gb/s. OTH leverages the amiliar Time Division Multiplexing(TDM) technique, allocating any type o trafc ow into fxed-size bit rames (time slots) that arethen switched by buerless network nodes and transmitted over the digital signal. OTH providesunique, well-proven capabilities or transport networking, such as cost-eectiveness and minimizedcomplexity, oering the best trade-os among networking exibility, hardware design simplicity andnetwork efciency. These OTH characteristics oer key advantages:

Transparency and multiservice Regardless o the nature o the transported service, in OTH anytype o client trafc, including IP packets, is encapsulated in rames that are switched in buer-less network nodes and transported through logical pipes, at a constant bit rate and guaranteedquality with deterministic perormance. This technique avoids the sophisticated trafc process-ing that is typical o packet technologies, such as classifcation, metering, queuing, Quality oService (QoS) and congestion avoidance. Particularly advantageous in regional or backbonenetworks, where the trafc o multiple services rom multiple access and metro locations isalready well consolidated, this approach is a simple, efcient method or transparent, reliabletransport over long distances.

Security In the electronic domain, OTH ensures that the networking technology used bythe transport layer is ully independent rom that used by the transported client service layer.This eature improves security against denial o service (DoS) attacks and guarantees ull clienttrafc segregation, paving the way or an efcient shared network inrastructure among multipleservice providers.


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4.1 OTN hierarchy

The OTN architecture encompasses three hierarchical transport layers, as shown in Figure 3:

Optical Transport Section (OTS) Optical regeneration section layer devoted to the managemento line optical amplifers and related links. The OTS represents a managed multi-wavelengthsignal over a single optical span (or example, between line amplifers).

Optical Multiplex Section (OMS) Optical multiplex section layer devoted to the management

and multiplexing o wavelengths, and thereore to the management o multiplexers/demultiplex-ers. The OMS represents a managed multi-wavelength signal over multiple optical spans (orexample, between DWDM equipment).

OCh Optical path layer devoted to the end-to-end management o wavelengths within theOTN. The OCh represents a single optical channel over multiple optical spans with exibleconnectivity.

Figure 3. OTN hierarchy: integrated bandwidth management of photonic and electronic transport domains

ODU switching

WDM switching

N:11:N

N:11:N

Line amplifier Line amplifier

OTS

Electronic domain

Photonic domain

WDM switching

ODU switching

OMS (multi-wavelength)

OCh (wavelength)

ODU (sub-wavelength)

The OCh signal consists o an Optical Payload Unit (OPU), Optical Channel Data Unit (ODU)and Optical Channel Transport Unit (OTU). The OPU provides the unctionality or mappingclient signals such as STM-64/OC-192, 40 Gigabit Ethernet (GE), 100GE and Fibre Channel(FC) into the ODU. The ODU is a network-wide managed transport entity that unctions as theprimary bearer or client trafc and can transparently transport a wide range o client signals. In-band ODU operational tools support managed transport services in multi-operator optical networksin a client-independent way that is essential to the operation o these networks. Such tools supportmonitoring unctions that enable SLA assurance or end customers, service providers and networkoperators. The tools provide or multiple levels o nested and overlapping connection monitoring aswell as reliable perormance using sophisticated ault localization capabilities.

Each ODU can carry a single client signal (Lower Order client container: LO ODU) with rates at1.25 Gb/s, 2.5 Gb/s, 10 Gb/s, 40 Gb/s and 100 Gb/s or it can carry multiple (multiplexed) client signals(Higher Order server container: HO ODU) with rates at 2.5 Gb/s, 10 Gb/s, 40 Gb/s and 100 Gb/s.


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In addition, a exible-sized ODU container (ODUex) has been standardized as capable o sup-porting the transport o variable-rate packet streams or example, virtual local area networks(VLANs) within a 100GE port to provide maximized bandwidth utilization and scalable trans-port o client services at the lowest cost per bit.

Robust protection schemes with deterministic perormance are available in the three hierarchicaltransport layers to ensure both network and client survivability under 50 ms, along with GMPLS

control plane-based restoration that supports exible options or network resilience againstmultiple ailures.

5. Efciently scaling the IP backbone

Today, most backbone trafc travels through multiple core routers to and rom its destination. Withrising bandwidth demands, pressure on core routers increases in kind: the routers throughput andport count increase in proportion to the overall transmitted trafc. Some operators are adding newrouters and ports; others are upgrading their core routers to multichassis confgurations and areadding corresponding WDM wavelength transport in the optical layer just ast enough to managetrafc growth. All this comes at a signifcant cost, power and carbon ootprint clearly not aneconomically efcient model when addressing the exaood phenomenon.

5.1 Opportunities for greater efciency

Analysis o trafc patterns across typical IP networks suggests that an overwhelming percentage otrafc passes through a relatively small number o locations or Internet peering, data centers andcontent distribution. Such transit trafc can represent as much as 75 percent o the overall trafc.This trend is likely to accelerate as video sharing, social networking and data center applicationscontinue to evolve, placing additional stress on backbone networks. In addition, these real-timevideo and multimedia applications demand ever more stringent latency and delay capabilities romthe network. Meeting such requirements is becoming a critical actor in determining the successo operators engaged in delivering high volumes o these services.

While certainly a challenge or service providers, these issues present a signifcant opportunity oroptimizing the core network architecture. Ooading trafc rom the IP core and handling it at theoptical transport layer drastically reduces costs by avoiding router trafc congestion and capacityover-dimensioning. Economic benefts are urther enhanced with intelligent control plane integra-tion, yielding increased resiliency.

Capable o supporting terabit networking, OTN serves as the convergence layer or transporting awide range o services whose bit rates do not allow efcient usage o the entire bandwidth associ-ated with a single wavelength (lambda). Eective transport o such line rates involves supportingsub-lambda multiplexing, leading to resource efciencies and cost savings. Moreover, by leveragingbuerless capabilities, an OTN-based backbone inrastructure ensures the low-cost transport olarge portions o real-time trafc with deterministic quality and perormance.


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5.1.1 Integrated ODUk client/line switching

Next-generation photonic networks with Reconfgurable Add-Drop Multiplexers (ROADMs) allowor OPEX savings, automation and resilience at the wavelength level. Such networks are comple-mented with an electronic ODU layer that adds service-oriented sub-wavelength exibility. Portand subport grooming introduces a switching and grooming layer below the 100G wavelength andcomplements the ROADM or all services that run below bit rates o 100 Gb/s.

DWDM transponders usually support one type o client interace to fll one wavelength. Trans-port o a service mix o GE, STM-16/OC-48, 10GE and 40GE cannot be achieved with a singletransponder, thereore resulting in inefcient bandwidth utilization. In contrast, ODUk client/lineswitching supports ull exibility in associating client ports with DWDM lambdas while handlingeach service with its own quality assurance and even protecting clients, ports and line-side services(see Figure 4).

Figure 4. DWDM OCh switching with or without embedded ODUk switching

CIF CIF CIF CIF

SP SP SP SP

OCh switching

nxnx

CIF CIF CIF CIF

SP SP SP SP

OCh switching

DWDM transponders DWDM with client/line switching

Client/line

switching

Client/line

switching

Dedicated muxponders, or switchponders, support the required client/line switching unctionality.They oer multiplexing o lower-rate black-and-white client signals into a higher-rate carrier within

the system. The multiplexed signal connects to the central abric, with the ollowing benefts:

Flexible client-to-line assignment through an independent abric

Sub-lambda grooming between line ports

Ultra-ast electrical protection and restoration o client signals

Restoration with a per-service SLA

Architecture with no single point o ailureThe ODUk layer allows or service dierentiation o transparent packet and TDM streams.Business-customer packet and TDM services can be delivered with the same network but withphysical trafc segregation separate rom the Layer 3 inrastructure. Moreover, as client serviceprotection is not supported on DWDM transponders, ODUk switches support Sub-NetworkConnection/Network Connection (SNC/NC) protection schemes that oer interoperabilitywith SDH/SONET networks.


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5.2 Beyond IPoWDM: efcient IP trafc grooming options

With OTN, the core routers can be efciently ooaded using a variety o IP trafc grooming op-tions: lambda-, port-, and subport-level. This capability minimizes the cost o transport relative tothe service providers trafc mix and approach to network integration because multiple groomingoptions beyond the lambda level deliver the greatest efciency and operational exibility. This iscentral to carrying out core network transormation and realizing the vision o intelligent OTN.Ooading must be done with ull assurance o service quality, the introduction o operational

simplicity, and ull control plane integration. With all these criteria met, providers can transitionefciently and cost-eectively to a next-generation OTN.

Typically, a wavelength in the optical layer at 10 Gb/s or 40 Gb/s or even 100 Gb/s in the mostrecent network deployments provides ar greater capacity than the overall amount o trafcbandwidth actually required between client peer nodes in the IP layer. As a result, many networkconnections do not require a ull lambda. In addition, depending on the service mix, client interac-es likely carry various trafc ows, each representing a logical channel between two dierent peernodes and requiring individual trafc orwarding to dierent destinations in the optical layer.

An intelligent OTN inrastructure enables multiple bandwidth management options with dier-ent granularities or maximizing the efciency o transport networks and lowering the total cost

o reliable transport according to the service mix and trafc distribution within the network. IPtrafc rom router ports and subports, such as VLANs within the same port, can be mapped to themost optimal transport granularity a wavelength (OCh), fxed-rate virtual container (ODU) orvariable-rate virtual container (ODUex) and then individually orwarded and managed acrossthe optical layer with the highest reliability and quality assurance.

These highly granular ow-management options allow service providers to ocus their routingresources on high-touch services that require more sophisticated treatment while moving transittrafc efciently and seamlessly across lower-cost optical inrastructures (see Figure 5).

Figure 5. Efficient IP traffic grooming with OTN

Efficient trafficgrooming options

Subport (VLAN) level

Port level

Lambda level

Service router OTN switch

Service-specifictransportcontainers

To peeringgateway

10G/40G/100G

To datacenter

OTN networking

GMPLS intelligence


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5.2.1 Subport-level grooming

Many incumbent providers and large operators oer both leased lines and a signifcant number oprivate Layer 2/Layer 3 data services, generating signifcant volumes o any-to-any trafc. Whenthese combinations make up a large portion o the overall trafc matrix, the fner granularity o-ered by subport-level grooming becomes essential to maximizing network resources and maintain-ing the lowest cost per transported bit.

Subport-level grooming is a highly granular, exible means o addressing growth, allowing maxi-mum grooming exibility by enabling VLANs or pseudowires within a router port to be logicallymapped to a transport container such as a fxed-rate ODU or variable-rate ODUex. For example, a3 Gb/s VLAN ow as a portion o a 10GE port is mapped to an ODUex, which is in turn groomedwith other ODUs into a 40 Gb/s OCh wavelength. Dierent VLANs rom the same router port aremapped to dierent virtual containers and are orwarded across the optical layer to their specifcdestination at the highest quality and lowest cost per bit.

Subport-level grooming enables fner granularity by supporting channelized or virtual interacessuch as VLANs, ensuring that IP router ports need not consume the ull capacity o an opticaltransport port or wavelength. Without such granularity, providers would be orced to overbuild theirIP and transport inrastructures not an ideal fnancial scenario. Most important, subport-level

grooming suits large service providers existing organizational structures and operational models,optimizing their transport inrastructure without requiring alterations to network operations.

5.2.2 ODUex: superior sub-level grooming

ODUex is a new technology that enables trafc grooming between optical transport equipmentand routers in a manner that efciently addresses incremental bandwidth growth, in steps as granu-lar as 1 Gb/s. Service providers no longer have to allocate a ull ODU container to each connection:they can increase capacity in increments. ODUex acilitates virtual channeling or 10 Gb/s,40 Gb/s and 100 Gb/s Ethernet interaces.

5.2.3 Port-level grooming

In addition to business services, most large operators oer residential broadband and Internetservices that inherently add hub-and-spoke type trafc to any-to-any connectivity within thenetwork. In these cases, a less granular grooming exibility is required to better utilize resources,achieve the lowest cost per transported bit, and avoid overbuilding in both the IP and opticalinrastructure domains.

With the port-level grooming option, a ull port is logically mapped to a transport virtual con-tainer typically a fxed-rate ODU pipe o the proper size. For example, a ull 10GE port is entirelymapped to an ODU2, which is in turn groomed with other ODUs into a 40 Gb/s or 100 Gb/s OChwavelength. Dierent ports rom the same service router or a dierent router can be mapped todierent virtual containers, groomed over a single wavelength, and orwarded across the opticallayer to their specifc destination at the highest quality and lowest cost per bit.


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Entering the Terabit Era | Strategic White Paper 11

5.2.4 Lambda-level grooming

Lambda-level grooming, also known as IP over WDM (IPoWDM), oers the lowest level o groom-ing exibility. For networks with very high volumes o hub-and-spoke trafc, it can be the optimalarchitecture because each physical port is equivalent to a single wavelength. In the lambda-levelgrooming model, a router port is mapped into a whole wavelength and the transport domain ispurely photonic. The OCh wavelength signal is optically switched across the OTN optical layerusing photonic switching capabilities and is delivered to its destination. With such a model, tran-

sponders can be hosted in the optical equipment or directly in the routing equipment. However,the latter option may prove impractical or existing organizational structures and operationalmodels o large service providers, and or guaranteeing high optical perormance, especiallyin long-haul applications.

5.3 Optimal lling of network resources

As trafc increases, service providers ace the challenge o deciding how and when to migrate tohigher bit rates in both IP and optical layers: rom the routers 10GE interace to an intermediate40GE interace and fnally to the 100GE interace and rom a 10 Gb/s link to a 40 Gb/s link ordirectly to a 100 Gb/s wavelength. Such approaches basically translate into the ollowing options:

a. Using n x 10GE link aggregation

b. Migrating to 40GE as an intermediate stepc. Migrating to 100GE

d. Optimized migration using router port virtualization

Link aggregation combines multiple parallel links into one large logical link although its use typi-cally decreases actual throughput efciency to about 60 percent. In addition, in a 100 Gb/s lambda-based DWDM network, when the frst 10GE port is connected to a DWDM transponder, the entire100 Gb/s wavelength is switched through the network although it is flled to only 10 percent oits capacity.

A ROADM-based network switches and restores the entire 100 Gb/s wavelength and provides noaccess to more efcient grooming and dropping o trafc within this wavelength. 40GE interacesare relatively less efcient when compared to available 100GE options but several operators seevalue in deploying 40 Gb/s wavelengths as a DWDM line rate or 4 x 10GE transport.

5.3.1 Virtualizing router ports using OTN grooming

Router port virtualization oers an efcient capacity handover to the OTN. Multiple 10GE portscan be combined into one 100GE interace, and the trafc can be logically separated into separatevirtual streams. For example, OTN subport grooming can combine three 100GE ports, each witha flling rate o 30 percent, into a single 100 Gb/s wavelength or optimized network efciency.

Along with the support o IP ooading options, OTN subport grooming oers efcient usageo low-flled router ports with port virtualization while both port and sub-port grooming provide

optimal wavelength flling in a DWDM network or maximized efciency and bandwidthmonetization. OTN grooming helps solving the cost-capacity crunch by efciently scalingIP metro and core networks.


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5.4 Service differentiation

Core networks do not exclusively transport best-eort IP trafc. There is a need to transport trafcrom multiple Internet service providers (ISPs) and business customers, transparent wavelengths orcarriers carrier applications, and legacy TDM trafc. This trafc mix requires a grooming layerseparate rom packet grooming.

All these dierent services can be groomed into 100 Gb/s lambdas to maximize bandwidth mon-

etization and can be protected and restored per service with high availability and quality assurancebased on their SLAs.

6. Taking quality assurance and operational simplicity to the next level

An essential requirement or a transport inrastructure is its ability to supervise the quality o thetransported services throughout the entire network. This is key to ensuring that SLAs are met andto the prompt enorcement o automated recovery actions in case o quality degradation.

Although existing transport technologies do support such eatures, new needs are emerging andposing additional challenges as service providers optical networks expand in both size and capacity.A service provider (or lead operator) oten needs to interconnect to another network operator todeliver end-to-end connectivity to its end customers. In such a multicarrier networking environ-ment, new capabilities are necessary. For example, lead service providers must be able to protectand supervise their customer services end-to-end including the portion o network capacity thatbelongs to other operators.

OTN expands the capabilities o transport networking to address those potential limitationsimposed by existing transport technologies that add to operational complexity and increasenetwork costs.

6.1 Enabling transparent capacity services for the carriers carrier

A service provider oten needs a capacity service rom another carrier (the carriers carrier) to oer

end-to-end connectivity to its customers. In some cases, the capacity service can be a GE connec-tion, but i service provider runs SDH/SONET, the capacity service o the carriers carrier must bean SDH/SONET connection.

As shown in Figure 6, i Provider B the carriers carrier uses SDH/SONET as the transporttechnology, it cannot transparently carry Provider As SDH/SONET payload and overhead becausethese would terminate in Provider Bs network upon multiplexing or cross-connection. As a con-sequence, Provider As network would be unable to support end-to-end resilience or example,with the use o SDH/SONET ring protection within its network. In such a case, Provider B couldpossibly deploy a passive all-optical solution. However, this would lack the supervision capabilitiesnecessary to ensure quality.

With OTN, the transparent transport o SDH/SONET capacity services is no longer an issue. AsProvider B deploys an OTN inrastructure, Provider As entire SDH/SONET rame is mapped intoan OCh container, which is transparently carried through Provider Bs network and provides thenecessary networking, supervision and resilience capabilities or a capacity service.

This approach allows a carrier to transparently carry the transport inrastructure o otherservice providers, enabling the delivery o transparent capacity services with simplifedend-to-end operations.


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Figure 6. Transparent transport of other carriers infrastructures with OTN

End userEnd user

SDH/SONET/

WDM network

SDH/SONET/

WDM network

OTN

network

Provider As infrastructure carriedtransparently for end-to-end operations

Provider AProvider A Provider B

(carriers carrier)

6.2 Enhancing quality control in a multicarrier environment

Supporting automatic SLA verifcation and ault localization in multicarrier scenarios is compli-cated. For example, existing SDH/SONET automatic supervision mechanisms such as tandemconnection monitoring (TCM) allow one network operator within a group to monitor the end-to-end connection, or they allow multiple network operators to separately monitor their own networks.Because it is not possible to concurrently automate both types o monitoring, SLA verifcation oten

requires tight intercarrier cooperation and oine processes that add signifcantly to operationalinefciencies and costs.

For example, i the decision is made to provide end-to-end monitoring, manual processes arerequired or ault localization. I the decision is made to provide per-operator monitoring, the leadoperator cannot determine overall signal quality. The lead operator would thereore need to relyon customer complaints or work to ensure the tight coupling o management systems across carrierboundaries. This lack o direct end-to-end monitoring or service assurance has long been a barrierto urther lowering operational costs.

By oering a ull set o quality supervision, connection monitoring and SLA verifcation capabili-ties or the easy and defnitive support o multicarrier scenarios, OTN helps carriers augment SLA

assurance levels or their end customers while dramatically lowering OPEX. As shown in Figure 7,ODU containers provide nested and overlapping supervision capabilities or every stakeholder in thetransport domain: client user, lead service provider and network operators.

For example, the customer can own the OCh endpoints and their monitoring capabilities whilethe lead service provider owns the OCh leased circuits or which the network operators provide theOCh connections. Two fxed levels o connection monitoring capabilities and six variable levels onested and overlapping connection monitoring are defned or this purpose.

Figure 7. Nested OTN monitoring levels: enabling efficient SLA assurance in a multidomain environment

Client user

Multi-carrier OTN network

Client supervision

Lead operator supervision

Provider AProvider A Provider B

Client user

Domain and interconnect supervision

Protection supervision


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6.3 Decreasing network recovery time

Many o todays data-network reliability problems are solved in the transport layer as the frst lineo deense against severe network aults such as fber cuts. Recovery rom these optical layer outagesmust be rapid given the ever-growing bandwidth and number o users per fber. OTN protectionmechanisms provide ast transport layer recovery or deterministic perormance. In general, provid-ing transport layer recovery as close as possible to the physical media layer tends to be the mostefcient solution minimizing the need or spare capacity across all aected upper layers as

well as reducing the number o transport entities involved.

6.4 Control plane intelligence for enhanced reliability and operations

Control plane intelligence is a key component o evolving OTNs in many critical aspects, enablingefcient bandwidth use and monetization. It also expands service quality assurance rom access tocore and provides graceul scaling, improved resiliency and simplifed, automated operations. Toreduce expenditures and respond to increasing bandwidth demands, OTN leverages the experienceo the Automatic Switched Optical Network (ASON)/GMPLS control plane intelligence requentlydeployed in todays optical networks.

GMPLS control plane-enabled OTN solutions simpliy network operations by delegating several keyoperational processes to the control plane or automation, yielding a sel-running network. Auto-mated processes include the discovery o network topology, resources and services, as well as end-to-end optical connection routing or optimal resource utilization, ow-through service provisioningand mesh restoration.

By supporting GMPLS control plane intelligence, an OTN inrastructure enables the ollowingbenefts:

Less need or manual and time-intensive operational procedures

Higher network monetization with optimized resource utilization

Better SLA assurance and network reliability provided by control plane-enabled restorationschemes, including protection and restoration combined (PRC)

Higher interoperability across multivendor, multilayer and multicarrier networks

Efcient tailoring o optical transport capacity according to IP layer demands

Rapid turnup o revenue-generating services

GMPLS allows or dynamic bandwidth provisioning at the most efcient level and oers resiliencyto multiple ailures as well as intelligent restoration mechanisms. When a ailure has been detectedin a given network path, the protection schemes switch the trafc to the protected path. The GMPLScontrol plane then recalculates the new protected pipe to ensure that additional support will beavailable should a new ailure arise. This process can be reiterated as many times as necessaryaccording to the availability o network resources, guaranteeing an always-on transport inrastruc-ture that is able to survive multiple ailures.

GMPLS restoration enables SLA assurance with minimum resource allocation, reeing up band-width that can then be used or additional paying trafc. Another key advantage o GMPLS isoperational simplicity. The network is sel-healing, removing the need or manual interventions andallowing operators to relax their schedules or on-site interventions while still ensuring the highestservice quality.


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6.5 IP and optical cross-layer control plane

For maximum operational control o network resources, rapid service provisioning and increasedresiliency, GMPLS user network interace (UNI) protocol enhancements enable a rich inormationexchange between the IP and optical-layer control planes. The standard UNI, with Alcatel-Lucentextensions, provides carrier-class resilience and acilitates cross-layer inormation sharing betweenthe optical and the IP networks, including:

Cross-layer control and automation

Dynamic OTN bandwidth allocation on IP demand

Fast provisioning

Non-disruptive elastic bandwidth modifcation

Cross-layer ault localization and reporting

Coordinated multilayer restoration

The cross-layer control plane solution leverages photonic and electronic switching to optimize net-work costs. The solution reduces CAPEX by orwarding and protecting bits at the most economiclayer, reeing expensive capacity. OPEX is also optimized by increasing service availability, providingsynergies and consistent operations and services across layers, and guaranteeing the highest network

power efciency.

7. Entering the terabit era with the Alcatel-Lucent 1830 PSS

The Alcatel-Lucent 1830 PSS portolio adds best-in-class multi-terabit electronic ODU switch-ing unctionality to its best-in-class DWDM networking capabilities 100G coherent, TunableROADM [T-ROADM], long optical reach, photonic OA&M, design tools, and more as provenby more than 70 customer deployments.

1830 PSS-641830 PSS-361830 PSS-321830 PSS-161830 PSS-41830 PSS-1


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Highlights o the Alcatel-Lucent 1830 PSS portolio include:

Single product integrating WDM and OTN switching modules

Scalable product size variants rom access (1830 PSS-1) to core (1830 PSS-64)

End-to-end networking in the WDM and OTN layers across product variants

Allows or sub-wavelength ODU switching and any-client/any-line assignment to maximizewavelength flling actors and add exible bandwidth management

New Alcatel-Lucent 1830 PSS-36 and 1830 PSS-64 shelves

Scalable multi-terabit OTN switching options at multi-terabit capacity

Support or any mix o client trafc

T-ROADM confgurations

Next-generation 40G/100G coherent optics

GMPLS control plane intelligence, ensuring the greatest possible network efciency

Cross-layer automation

Highly resilient transport

Dynamic bandwidth provisioning

Common network management

Common cards across the product portolio

7.1 Alcatel-Lucent 1830 PSS-64 and 1830 PSS-36

The new Alcatel-Lucent 1830 PSS-64 and 1830 PSS-36 orm actors oer integrated terabit OTNand DWDM capabilities or the next-generation intelligent optical core. These advanced opticalswitches manage trafc at the most economical layer. Extensive automation and GMPLS controlplane intelligence minimize the need to reserve network capacity or resiliency. Instead, providerscan operationalize more o their available bandwidth, generating additional revenue and maximiz-ing profts.

The Alcatel-Lucent 1830 PSS-64 and PSS-36 eature a unique set o capabilities:

Multi-terabit switching architecture

State-o-the-art 2 Tb/s capacity

120 Gb/s per slot backplane with built-in readiness to upscale to 8 Tb/s

Universal switch unit that can support any trafc mix

100 percent TDM to 100 percent packet

Single compact, highest-density chassis

Lowest power per transported bit

Very low power consumption (less than 2 W per Gb/s)

Support o OTN

Multiple transport networking options, including OTH, Carrier Ethernet, SDH and SONET

Most efcient bandwidth management o low-rate signals (GE, STM-1/OC-3)

Up to 40 Gb/s or 100 Gb/s

Flexible IP trafc grooming options at the OTN layer, including port-level and subport-level grooming

GMPLS control plane

Enables ast restoration and protections schemes at ODU-layer service granularity

Ensures superior SLAs


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7.2 Economically viable 100G deployments

The Alcatel-Lucent 100G polarization division multiplexing - quadrature phase-shit keying(PDM-QPSK) coherent solution is commercially available with signifcant market traction sinceits launch in June 2010. Since then, Alcatel-Lucent has deployed its optical 100G solution indozens o networks worldwide.

The Alcatel-Lucent 1830 PSS solution supports single-carrier 40G and 100G coherent detection.

This 100G solution is unique in the market, providing: Ultra-ast electro-optical analog-to-digital converter/digital signal processing (ADC/DSP)

at 25+ Gbaud real-time processing, developed by Alcatel-Lucent Bell Labs

High transmission perormance as well as high tolerance to physical impairments

Full compatibility with existing 10G and 40G channels

High level o integration in the complementary metal oxide semiconductor (CMOS),or lower cost/power consumption

Compliance with the ITU 50 GHz wavelength grid, ully tunable across the C band

Elimination o the need or external polarization mode dispersion/chromatic dispersion(PMD/CD) compensators

High-capacity 100G coherent modulation is a key component in building scalable converged OTNand photonic networking solutions. 100G applications are expanding rapidly and have proved tobe economically viable compared to 10G and 40G deployments. Typical applications include:

Plug-and-play 100G line cards in existing 10G networks when capacity is exhausted

Lower cost per bit and dispersion compensation module (DCM)-ree networks orgreenfeld deployments

100GE interconnection or IP-optical integration

IP ooading, achieving the lowest cost per transported bit

8. Conclusion

OTN supports efcient IP trafc growth and maximizes the value o the network without com-promising service levels. Able to support massive bandwidth growth while maintaining transportexpenses at the lowest cost per bit, OTN allows service providers to ully monetize their trafc andtake economic advantage o rising demands.

Drawing on our established WDM and cross-connect technology leadership, Alcatel-Lucent has ex-panded our leading WDM portolio with a rich set o integrated terabit OTN switching capabilities.The Alcatel-Lucent 1830 PSS portolio oers service providers the oundation or a next-generationtransport inrastructure: one that is capable o cost-eectively scaling the IP backbone and enteringthe terabit era.


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9. Acronyms

OMS Optical Multiplex Section

OPEX operating expenditures

OPU Optical Payload Unit

OTH Optical Transport Hierarchy

OTN Optical Transport Network

OTS Optical Transport Section

OTU Optical Channel Transport Unit

P provider

PDM-QPSK polarization division multiplexing -quadrature phase-shift keying

PE provider edge

PMD polarization mode dispersion

PRC protection and restoration combined

QoS Quality of Service

ROADM Recongurable Add-Drop Multiplexer

SDH Synchronous Digital Hierarchy

SLA Service Level Agreement

SNC Sub-Network Connection

SONET Synchronous Optical Network

SP service provider

T-ROADM Tunable ROADM

TCM tandem connection monitoring

TCO total cost of ownership

TDM Time Division Multiplexing

UNI user network interface

VLAN virtual local area network

WDM Wavelength Division Multiplexing

ADC analog-to-digital converter

ASON Automatic Switched Optical Network

CAPEX capital expenditures

CBT Alcatel-Lucent Converged BackboneTransformation Solution

CD chromatic dispersionCIF client interface

CMOS complementary metal oxide semiconductor

DCM dispersion compensation module

DoS denial of service

DSP digital signal processing

DWDM Dense WDM

FC Fibre Channel

GE Gigabit Ethernet

GMPLS Generalized MPLS

HLN High Leverage Network

HO Higher Order

IP Internet Protocol

IPoWDM IP over WDM

ISP Internet service provider

ITU-T Internat ional Telecommunicat ion Union -Telecommunication Standard

LO Lower Order

MPLS Multi-Protocol Label Switching

NC Network Connection

OA&M operations, administration and mainte-nance

OCh Optical Channel

ODU Optical Channel Data Unit


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www.alcatel-lucent.com Alcatel, Lucent, Alcatel-Lucent and the Alcatel-Lucent logoare trademarks of Alcatel-Lucent. All other trademarks are the property of their respective owners.The information presented is subject to change without notice. Alcatel-Lucent assumes no responsibilityfor inaccuracies contained herein. Copyright 2011 Alcatel-Lucent. All rights reserved.CPG1076110435 (06 )

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