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Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs — Delivering Flawless Quality of Experience to Residential and Commercial Customers The cable MSO networks of the future will be converged communications networks that effortlessly deliver video, multimedia and on-demand services to residential and commercial business customers. To make this possible, cable multiple service operators (MSOs) are transforming their networks through a convergence of consumer, business and mobile services over a common Internet protocol/multiprotocol label switching (IP/MPLS) infrastructure. But to meet customer expectations, cable MSOs must look beneath the underlying network infrastructure to the routers that route services. Those routers must be advanced, service routing platforms that enable delivery of today's and tomorrow's high-performance video, high-speed data and voice/mobility services to residential, small-medium enterprise (SME) and large enterprise customers with a high level of quality and service reliability. This paper looks at the requirements of the evolving cable MSO network architecture. It outlines the roles reliability, quality and service management play in the network infrastructures required to meet residential and commercial business expectations for next generation services. And it presents the Alcatel-Lucent approach to reliability, quality and service management, which can help cable MSOs build cost-optimized, highly-available and feature-rich service delivery networks for residential and enterprise requirements. TECHNOLOGY WHITE PAPER

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Converged, Service-Aware IP/MPLS Network Architecturefor Cable MSOs — Delivering Flawless Quality of Experienceto Residential and Commercial Customers

The cable MSO networks of the future will be converged communications networks

that effortlessly deliver video, multimedia and on-demand services to residential and

commercial business customers. To make this possible, cable multiple service operators

(MSOs) are transforming their networks through a convergence of consumer, business

and mobile services over a common Internet protocol/multiprotocol label switching

(IP/MPLS) infrastructure.

But to meet customer expectations, cable MSOs must look beneath the underlying network

infra structure to the routers that route services. Those routers must be advanced, service

routing platforms that enable delivery of today's and tomorrow's high-performance video,

high-speed data and voice/mobility services to residential, small-medium enterprise (SME)

and large enterprise customers with a high level of quality and service reliability.

This paper looks at the requirements of the evolving cable MSO network architecture.

It outlines the roles reliability, quality and service management play in the network

infrastructures required to meet residential and commercial business expectations for next

generation services. And it presents the Alcatel-Lucent approach to reliability, quality and

service management, which can help cable MSOs build cost-optimized, highly-available

and feature-rich service delivery networks for residential and enterprise requirements.

T E C H N O L O G Y W H I T E P A P E R

Table of Contents

1 1 Introduction

3 2 Including the Business Factor

5 3 The Benefits of Service Routing

7 4 Service Reliability: Making Network Outages a Thing of the Past

7 4.1 Leading Hardware Availability

8 4.2 Unmatched Routing Resiliency

8 4.3 Non-Stop Routing and Non-Stop Service

10 4.4 In-service Software Upgrades

10 4.5 High Performance Link Resiliency

11 4.6 Mitigating DoS Attacks

12 5 Service QoS: The Cornerstone of Service Velocity

12 5.1 Network and Service Capacity Planning

12 5.2 Service Awareness

14 6 Service Management: Improving Operational Efficiency

14 6.1 OAM Tests

15 6.2 Timely Fault Isolation

16 7 Conclusion

18 8 Acronyms

1Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

1 IntroductionFueled by ever-increasing customer expectations and relentless competition, tomorrow’s cableMSO networks must be more service-oriented and user-centric. They must continue to deliverresidential services and evolve those offerings with triple play and quad play services to meetcustomer demand. At the same time, they must support new ventures into commercial marketsto attract business and wholesale customers. This dual role is driving the transformation of cableMSO networks through a convergence of consumer and commercial retail and wholesaleservices over a common Internet protocol/multiprotocol label switching (IP/MPLS) network.Transformation is also playing a big role in the development of DOCSIS 3.0, universal edgeQuadrature Amplitude Modulation (QAM) and modular cable modem termination systems(M-CMTS) that provide cable MSOs more flexibility to scale upstream and downstreamcapabilities.

The converged, service-aware IP/MPLS infrastructure (Figure 1) provides a multi-serviceaggregation network that allows cable MSOs to embrace these new advances in cabletechnology within the existing cable architecture and benefit from economies of scale, simplifyservice delivery, and increase service flexibility.

Figure 1. Converged, Service-Aware IP/MPLS Network Architecture

The wide spectrum of residential and commercial services that can be supported over a commonIP/MPLS network will help increase average revenue per user (ARPU) for:• Residential services, such as:

¬ High-speed Internet and home phone (VoIP)¬ Switched broadcast video, which enables cable MSOs to reclaim bandwidth and expand

offerings to include hundreds of standard definition and high definition programs, long-tail content, and other service expansions

ResidentialServices

Business ServicesSME and Large Enterprises

VoD andAd Servers

Headend

DigitalSource

AnalogSource

HSI

VoiceGateway

DistributionHub

DistributionHub

HFC(DOCSIS 2.0, 3.0)

Home Run Fiber

DistributionHub

Multi-Service AggregationNetwork (IP/MPLS)

Converged Servicesover IP/MPLS Network

MobileBackhaul

Quality of Experience

2 Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

¬ Switched unicast services like video on demand (VoD) that allow cable MSOs to includetargeted advertising and increase personalization of content to enhance a subscriber’sviewing experience

¬ New consumer services enabled by PacketCable 2.0, IP multimedia subsystems (IMS),mobility, open cable applications platform (OCAP) and other advancements that enrichthe user’s experience

• Business services to SMEs and large enterprises to support: ¬ A new wave of multimedia and “on-demand” IP-based applications on which SMEs and

large enterprises are becoming increasingly reliant, such as global teleconferencing, VoIP,and digital media requirements. These applications are as demanding as they are sensitiveto shortfalls in bandwidth, latency, jitter and overall predictability. While less than voicequality might have been acceptable for older applications, SMEs and large enterprisesneed and will only accept superior delivery standards and performance for these new services.

¬ Wireless backhaul services to address the wireless industry’s need for high capacity solutions.The wireless industry is undergoing a transition as networks that were built 10 years agoare being upgraded to support new multimedia service offerings. This opens the door forcable MSOs to offer competitive solutions to meet the wireless operators’ bandwidthcapacity demand and stringent quality of service requirements.

As these services and applications are introduced, assuring the highest quality of experiencefor consumer and commercial business users is even more critical to maximizing profits.

In this environment, service differentiation and reliability can arguably be a cable MSO’sbiggest challenge. These service attributes are required to deliver uninterrupted subscribersessions, meet stringent service level agreements (SLAs) and even deliver life-line services.They are the key to competitive differentiation, customer retention and maximizing profits in today’s highly competitive environment.

These dynamics are placing ever increasing demands on the cable MSO network infrastructure.Especially on existing IP routing/switching elements required for the IP/MPLS infrastructure thatcable MSOs rely on to aggregate their hybrid fiber coax (HFC) network and support commercialbusiness services over home run fiber, at the regional headends or distributed hub sites.

To address the new demands on cable MSO networks, new service routing platforms are requiredthat have purpose built hardware and software architectures that guarantee the highest levelsof service availability and service quality than routers designed for enterprise or Internet-onlyapplications. In addition, service management must be tightly integrated with these servicerouters to ensure ongoing service reliability and minimize oper ational costs.

With the right service routing platforms, cable MSOs can transform their IP/MPLS networksto advanced service delivery infrastructures that can meet the high quality of experiencerequirements necessary to support the next generation of consumer services and deliver onthe new wave of IP-based business services. Service routing enables the delivery of high-performance video, high-speed data, voice/mobility services and advanced services to resi dentialand commercial business customers with a high level of quality and reliability.

3Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

2 Including the Business Factor Commercial services have become an area of intense focus as cable MSOs leverage their brandbeyond the residential market to develop new revenue. Attacking the commercial servicesmarket has deep significance because the change dynamics resonate on multiple levels thataffect business growth, market share and total cost optimization.

First, cable MSOs can capture a bigger share of the retail business services market. Accordingto Heavy Reading the U.S alone generates tens of billions of dollars annually for business ser -vices with less then 1% going to cable MSOs. Cable MSOs’ initial approach to the retailbusiness services market is driven by the belief that SME customers are poorly served by theTelcos. VoIP is seen as the inflection point that cable MSOs will lead with as part of theirbundled service offering, which will include business VoIP, data, and business video at anattractive price point and all on one bill. This approach is supported by Heavy Reading’sresearch illustrated in Table 1.

Table 1. SME Primary Service Preferences for MSOs

REASON % OF RESPONDENTS

VOIP 88.24

High-speed Internet 70.59

Dedicated IP 38.24

IP VPN 38.24

Video 29.41

Circuit-switched Voice 23.53

Ethernet 11.76

Storage Extension/Disaster Recovery/Business Continuity 5.88

WDM –

SONET Optical (OCn) –

Other 2.94

Source: Heavy Reading “Cable vs. Telcos: The Battle for the Enterprise Market” 2006

In the business services market, however, cable MSOs will face a different set of challengesthat are not inherent in the residential market. Today’s SMEs and large enterprises relyincreasingly on the successful and cost-effective deployment of information technologyapplications to drive sales, improve customer relationships, cut operating costs and simplifyprocurement. These applications are the lifeblood of the SME and large enterprise, so theirperformance can mean the failure of the SME or the large enterprise. Therefore, a cable MSOmust rely on the deployment of a flexible, scalable, and resilient network architecture onwhich to deliver services. To outmaneuver the compe tition, that architecture must support arich set of applications and connectivity models that can be augmented and scaled quickly.

Second, cable MSOs can leverage a converged network to address the wholesale aspect ofcommercial business.

The need for higher capacity is reshaping today’s wireless backhaul and backbone networks.Addressing backhaul capacity represents much of the cost of operating a mobile network. To do this, today’s base stations must scale from their current average capacity of 2-3 MBs to50-70 MBs in future — and up to 100Mbit/s for the most intensive 4G applications. A recentYankee Group report estimated that wireless service providers spend approximately 30 percentof their revenue on technical operations. Of this, nearly two-thirds is used to pay for backhaul.

4 Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

A converged, service-aware IP/MPLS network that is designed to deliver stringent QoS andhigh availability puts the cable MSOs in an ideal position to compete for this business.

Third, cable MSOs can optimize costs by consolidating residential and commercial businessservices on a common network that integrates services from their existing HFC plant andutilizes home run fiber to service larger enterprise and wholesale customers.

Service-aware IP/MPLS technology is the key enabler for converged networks supportingresidential and business services. It supports the delivery of video and voice, and enriches theservice mix with sup port for business virtual private networks (VPNs). It also enables cableMSOs to augment their existing cable services with a greater selection of competitively pricedLayer 2 and Layer 3 wide area network (WAN) Carrier Ethernet services by leveraging thestability and scalability of an MPLS control plane with the flexible bandwidth and economicsof Ethernet. As a result, cable MSOs can differentiate their Carrier Ethernet service andaddress a wider range of business customers — all on a common network, (Table 2).

Table 2. Enterprise Requirements for Business VPN Service Selection

POINT-TO-POINT CONNECTIVITY MULTIPOINT CONNECTIVITY

Enterprise Profile

Service

Enterprise Benefits

Metro Ethernet Forum (MEF) Carrier Ethernet services such as E-LAN (VPLS) and E-Line(VLL) have proven to be successful where offered and the opportunity exists to capture signif -icant revenue by scaling the size of these deployments. According to Infonetics, the CarrierEthernet service market is to surge 171 percent from 2006 to 2010, when it will top $25 billionworldwide. Further, according to In-Stat, ELAN (multipoint) services are expected to grow at a rate higher than ELINE (point-to-point) services with revenues for ELAN services pro jectedto hit $1.5B by 2010 for the U.S. market alone.

• Small number of sites

• Migrating from point-to-point frame relay service

• May not use VPN services today

• Usually requires a hub-and-spokenetwork topology

VLL (E-Line)

• Point-to-point Ethernet service over MPLS

• RFC 3916 (PWE3)

• Flexible bandwidth upgrades in fineincrements (e.g., 1 Mb/s)

• Service performance guarantees

• Service interworking provides fastermigration/integration

• Easy upgrade path to other MPLS-enabled Ethernet VPN services

• Medium-to-large number of sites

• Running IP-based applications only

• Requires full mesh connectivity

• Willing to share routing responsibility

IP-VPN

• Multipoint routed solution over MPLS

• RFC 4364 (obsoletes 2547bis)

• Offload complex information technology(e.g., routing) responsibilities to serviceprovider

• Fully meshed service supports multipleaccess types

• Option of Ethernet or maintain framerelay to access WAN

• Medium-to-large number of sites

• Running IP- or non-IP-based applications

• Migrating from transparent LAN services

• Requires full mesh connectivity

• Unable or unwilling to share routingresponsibility

• Ethernet hand-off

VPLS (E-LAN)

• Multipoint bridged solution over MPLS

• RFC 4762

All the advantages of an IP VPN solutionplus:

• Addition of new sites requires no changeto existing sites

• Retains control over routing functionality

• Multiprotocol service supports the use ofnon-IP applications

• Can make changes to the network withoutinvolving service provider

• Service interworking between frame relayand Ethernet allows gradual site-by-sitemigration, minimizing service disruption

5Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

Additionally, high margin value add enhancements such as SLA enforcement and QoSenforcement can be added to base-level connectivity packages. Enabled by service routing,this flexibility provides a competitive advantage for delivering the next wave of high-valueresidential, business and mobile backhaul services.

In short, to properly realign themselves to address the residential and commercial businessmarkets requires cable MSOs to have the right mix of services to offer. This requires a carefulcombination of technology selection and architecture for a lasting investment that candeliver higher levels of relia bility and QoS, while offering better service management,scalability and performance. But, today’s choices should not limit future services or compelcable MSOs to deploy inefficient overlay networks in order to be responsive to customerneeds. Maintaining service reliability, service velocity and rapid provisioning is the key tocapturing the first-mover advantage with new offerings and is a direct component of overallrevenue. That advantage comes from a properly designed network.

3 The Benefits of Service RoutingThe goal of effective network design is to deliver services where any network event, planned orunplanned, is not detected by end users. Depending on the nature of the service being offered, itscontractual obligations and associated penalty clauses, various degrees of availability, resiliencyand redundancy can be engineered to meet customer expectations using a suite of technologyoptions. This requires a comprehensive solution that can mitigate network outages, providetimely fault isolation mechanisms, leverage optimal network design techniques and streamlineoperation and maintenance processes to ensure business continuity for the cable MSO and its customers.

Alcatel-Lucent is at the forefront of the development and delivery of service-aware IP/MPLSnetworks. It has set the new benchmark for IP routing to meet the exacting requirements ofcable MSO networks for:• Service Reliability – In today’s competitive environment, cable MSOs must meet their customers’

expectations for uninterrupted service. To do that they need comprehensive high availabilityfeatures that cover the node, the network and the service and enable sub-50 ms restorationfor thousands of simultaneous services for residential and commercial business markets.

• Service Scale and Performance – With the introduction of real-time, on-demand businessapplications the challenge facing cable MSOs is that they must scale in many dimensions,including network infrastructure, number of customers and services, without impactingperformance.

• Service QoS – By bundling voice, video and data services cable MSOs can deliver highervalue services. However, to enable service velocity the converged, service-aware IP/MPLSnetwork needs to ensure strict quality guarantees on real-time voice, video and businesscritical data applications for both residential and commercial customers.

• Service Management – Management systems have to evolve beyond the disparate elementmanagement platforms. To support a comprehensive set of element, network and servicelevel operation, administration and maintenance (OAM) tools, advanced managementsystems must provide cable MSOs with rapid fault management, ensure fast service activa -tion, provisioning and provide SLA performance metrics for latency, jitter and packet lossfor all traffic types.

6 Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

Alcatel-Lucent’s IP/MPLS solution enables cable MSOs to ensure their network meets thehigh quality of experience requirements necessary to deliver the new wave of next generationvideo and IP-based services. As well, it enables the network to support multicast routing andassure the IP backbone is capable of dealing with new demands that are placed on it frombroadcast video and IMS (Figure 2).

Figure 2. Meeting the Changing Service Requirements of Cable MSOs

The foundation of the Alcatel-Lucent solution is the Alcatel-Lucent IP portfolio, which includesthe Alcatel-Lucent 7750 Service Router (SR), Alcatel-Lucent 7710 SR and the Alcatel-Lucent7450 Ethernet Service Switch (ESS), and the Alcatel-Lucent 5620 Service Aware Manager(SAM). The Alcatel-Lucent service router and Ethernet service switch/router family of productscan be deployed at the regional headend and distributed hub sites where performance, IPservice scale, relia bility and service assurance are critical.

Industry standardization ensures Alcatel-Lucent solutions are smoothly introduced into cableMSO networks. Certified by the Metro Ethernet Forum (MEF) for MEF 9 and MEF 14, theAlcatel-Lucent service router and service switch are the platforms of choice for cable operatorswho want to deploy robust and highly reliable MEF-certified networks. They are the premierplatforms for migrating legacy video, voice, and data services onto a converged, metro-transportarchitecture because they simplify the operational costs associated with man aging and main -taining application specific networks.

ResidentialServices

Business ServicesSME and Large Enterprises

Telemedicine, E-learning,Collaboration, Digital Media Delivery and Management,Secure Payer Networks

E-govt., VideoArraignment, Data/Record Management

ERP, SCM/RFID,Collaboration, E-learning

Digital Publishing, DigitalMedia Delivery, Digital Asset Management and Archiving

CRM, SCM/RFID, POSKiosks, Surveillance

CRM, Data Warehousing,Outsourcing

Research nets, GridComputing, E-learning,Imaging, Simulation

VoD andAd Servers

Headend

DigitalSource

AnalogSource

HSI

VoiceGateway

MobileBackhaul

7750 SR

Service Scale and Performance

Converged, Service-AwareIP/MPLS Network

Service Management

Service QoS

Service ReliabilityDistribution

Hub

7750 SR7450 ESS

PWE3

Education

Finance

Medical

Govt.

Manuf.

Media

Retail

IP VPN

VPLS

D2A

EQAM

CMTS

Quality of Experience

7Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

4 Service Reliability: Making Network Outages a Thing of the Past The lack of hardware and software self-healing capabilities and hitless upgrade processes inlegacy routers prevent cable MSOs from delivering always-on IP/MPLS services. To properlyaddress these concerns, service reliability cannot be an added feature of a router. It mustpermeate every aspect of router design to mitigate the issues that cause network outages asshown in Figure 3.

The Alcatel-Lucent service routing solution is designed from the ground up to deliverunparalleled resiliency router mechanisms designed to enable highly available services andenforce stringent SLAs during planned and unplanned network events.

Figure 3. Alcatel-Lucent Service Routers Reduce Causes of Network Failures

4.1 Leading Hardware AvailabilityThe Alcatel-Lucent IP portfolio implements a number of essential hardware designs that ensurehigh availability. The modular hardware architecture of the service routers plays a key role inservice reliability.

A distributed design separates the control plane from the data plane and each system is equippedwith redundancy on common components to eliminate any single point of failure. Componentredundancy includes the control complex, switch fabric, power supplies and cooling fans. Inaddition, the chassis design allows for in-service insertion and removal of these modules,thereby eliminating service downtime due to module failure.

The control complex and switch fabric are integrated in the same module. Containing the switchfabric in a single module, rather than multiple modules, greatly minimizes service interruptiondue to switch fabric failure. The redundancy mechanism of the integrated control complex andswitch fabric ensures that 100% of the system bandwidth is always available.

The modularity of the line cards also significantly reduces mean time to repair (MTTR) andsimplifies sparing. The input-output modules (IOMs), media dependant adapters (MDA),compact media adapters (CMA) and optics are all hot pluggable and modules are portableacross the portfolio.

RouterMisconfiguration

36%

Milliseconds00:00:00:0X

Other Causes9%

Service Router

Link Failures23%

IP Routing Failures32%

Non-stop services and non-stop routing• Router self-recovers; transparent to neighbors• Orders of magnitude faster than graceful restart and no adverse effects to peer routers• Control plane failure results in zero service downtime for all services (IP-VPNs, VPLS, VLL, IES, triple play)• Non-stop VoD (IP unicast) and switched broadcast video (IP multicast)

Graceful restart (GR)• Uses neighbors to help recovery• Uses NSF during recovery

Non-stop forwarding (NSF)• Router continues forwarding traffic during recovery

Protocol reconvergence• Standard operation of routing networks; route around the failed node

00:0X:XX:XXMinutes

Mean Time to Repair

Triple Play andBusiness Services

InternetAccess

8 Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

4.2 Unmatched Routing ResiliencyThe software architecture also plays a key role in service reliability. The Alcatel-Lucent IP port folio was designed from inception to meet the high availability requirements of always-onIP/MPLS services.

4.3 Non-Stop Routing and Non-Stop Service Non-stop routing and Non-stop service are intelligent, hitless solutions for control planefailures. This means that if a software or hardware control complex fault occurs, there are noresulting service outages and no SLA violations.

In triple play service delivery for example, quality of experience requires high availability onmulticast protocols to ensure uninterrupted viewing. With multicast traffic, the redundancy is performed by protocol independent multicast-sparse mode (PIM-SM) and Internet groupmanagement protocol (IGMP). During a control plane failover, the service router continuesto process change reports to ensure non-stop broadcast video delivery.

In addition, IGMP stateful switchover — a mechanism to preserve IP multicast group mem -bership in the event of a CPM failover — provides the ability to continue processing newIGMP joins directly after a CPM failover, giving the subscriber non-stop service and theability to change channels during this event.

N O N - S TO P R O U T I N GAlcatel-Lucent has set a precedent with the non-stop routing feature in the IP portfolio. Inrouter designs from some vendors, a router control complex failure causes a reboot, which canlead to traffic loss and network instability until routing adjacencies are re-established and thetopology converges. The Alcatel-Lucent IP portfolio implements a number of industry-leading features to ensure a control plane failure has no impact on service delivery.

The hot standby control complex redundancy mechanism synchronizes the active and standbycontrol processor module (CPM) to prevent any inconsistencies in the event of a CPM failure.This ensures that the standby CPM is always ready to go with the latest router image, con -figuration and network state.

This proven technology makes it possible for a router to maintain active protocol sessions withadjacent routers and learn new routes during control complex failovers. Non-stop routing isextremely comprehensive and provides support for:• Border gateway protocol (BGP), including IPv6• Intermediate system to intermediate system (IS-IS), including IPv6• Open shortest path first (OSPF), including IPv6• Routing information protocol (RIP)• Virtual router redundancy protocol (VRRP)• Protocol independent multicast (PIM)• Internet group management protocol (IGMP)• Resource reservation protocol — traffic extension (RSVP-TE)• MPLS label distribution protocol (LDP) and targeted LDP signaling protocols

If a CPM switchover occurs with the Alcatel-Lucent solution, a reliable and deterministicswitchover to the standby CPM occurs such that there is no impact to routing processes(Figure 4), topology and reachability, and routing neighbors are unaware of a control complex fault.

9Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

Figure 4. Seamless Service Switchover

In BGP, for example, during a CPM switchover, existing BGP peers do not experience anychange and perceive a peer system that continuously supports dynamic routing. In addition,all routes are up-to-date and not stale, so there are no routing black holes or loops.

In OSPF and IS-IS environments, all adjacencies are maintained during the switchover.

For cable MSOs using VRRP in static routing environments as a method of protecting againsthaving one router as a single point of failure, non-stop routing ensures VRRP adjacencies andsessions remain intact after a control plane failover.

Finally, LDP adjacencies, sessions and forward equivalency class (FEC) databases remain intactafter a switchover and the LDP peers do not detect any adjacency change after the switchover.This feature includes support for both direct LDP and targeted LDP.

Other vendors have implemented graceful restart to address control plane resiliency. However,graceful restart is not a self-contained solution and requires that the failed router re-learn allthe routes. To do this it must get this information from neighboring routers. This can causedisruptions in the network and also creates a lot of overhead as information is being relayedacross the network.

In addition, with graceful restart, as the router waits to get routing updates from its neighbors,it continues to forward traffic based on the inaccurate routing table information. This oftenleads to loss of data and black-holed traffic.

However, to help legacy routers recover from a router processor failure, the Alcatel-Lucent IP portfolio does support graceful restart helper mode.

N O N - S TO P S E R V I C EAlcatel-Lucent takes reliability to an even higher level with non-stop service.

Non-stop service is the result of applying Alcatel-Lucent’s high availability expertise toIP/MPLS services. With non-stop service, customer-centric services, such as IP VPN, virtualprivate LAN service (VPLS), virtual private wire service (VPWS) and enhanced Internetservices are not affected during a control complex switchover. This mechanism fully ensuresthat service level guarantees are main tained at all times, allowing cable MSOs to uphold theircustomer service availability targets.

For example, in order to successfully maintain a VPLS service, the VPLS MAC address tableis preserved through a control complex failover. Non-stop service also includes the ability toprotect a VPW with a pre-provisioned, explicitly routed label switched path (LSP) for bypassprotection in the event of a network failure.

CFM B

CFM A

10 Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

4.4 In-service Software UpgradesThe Alcatel-Lucent service router portfolio was the first to deliver in-service software upgrades(ISSU). It is the only implementation that can guarantee no service outages and no SLAviolations during upgrades (Figure 5).

Figure 5. Alcatel-Lucent’s Industry-leading in-Service Software Upgrades

The Alcatel-Lucent ISSU solution leverages non-stop routing to ensure there is no loss ofservice during a CPM maintenance upgrade. The new software image is first downloaded to thestandby CPM. Once the standby CPM is running the new image, a switchover to the standbyCPM is ini tiated. This ensures microsecond convergence between the two CPMs. The newsoftware image is then downloaded to the other CPM to complete the process.

With IOM redundancy that uses link resiliency mechanisms such as link aggregation or auto -matic protection switching, the ISSU ensures there is minimal service impact during IOMupgrades. In addition, the operator can use service layer OAM ping tools, such as VPLS pingor VPRN ping, to verify that services are fully functional after the upgrade.

4.5 High Performance Link ResiliencyService reliability can also be affected by a link failure. The advanced architecture of theAlcatel-Lucent IP portfolio provides a tight link between a leading hardware availabilitydesign and self-healing resiliency mechanisms to ensure throughput around a link failure.

MPLS fast reroute (FRR) switches traffic onto a backup LSP, based on pre-calculated and pre-established backup paths, until a more appropriate backup path has been established. Fast re-route on the Alcatel-Lucent IP routers has industry leading performance and is capable ofrestoring up to 4k of LSPs per second. FRR also includes the tunneling of an LDP LSP insidean RSVP-TE tunnel for sub-50 msec service restoration of an LDP LSP.

Link aggregation group (LAG), which uses multiple Ethernet links to provide redundancy, is another effective mechanism to deal with the failure of one or more links. LAG adds nodelevel redundancy, in addition to link level redundancy, allowing two systems to share acommon LAG endpoint.

Alcatel-Lucent’s LAG implementation is extremely flexible. For example, upon the failure ofone link, traffic can be balanced across some or all non-failing links and the LAG group canspan more than one input module. In addition, the Alcatel-Lucent IP portfolio allows activeLAG member selection based on SLA enforcement constraints to ensure QoS is met whilethe maximum number of links is utilized.

Standby CPMSwitchoverfrom Activeto Standby

No Lossof Traffic

Active CPM

Download NewSoftware Image

11Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

Bidirectional forward detection (BFD), a lightweight network protocol with low overhead, is an efficient way to monitor and detect failures in the forwarding path between two routers.The Alcatel-Lucent implementation enables BFD sessions across static routes, OSPF, IS-ISand PIM protocols, along with enhanced Internet service interface. The Alcatel-Lucent IPportfolio is capable of providing sub-second convergence and will scale well, without servicedegradation to the data path.

For example, in triple play service delivery architectures, PIM-BFD is used to notify a servicerouter of a PIM router adjacency loss. Here, Alcatel-Lucent’s BFD implementation can reducethe recovery time for PIM-router adjacencies, even in large scale deployments, to the order of200-300 ms.

For non-Ethernet interfaces, automatic protection switching (APS) is used to switch traffic toa backup SONET/SDH or ATM link in the event of a failure. The Alcatel-Lucent IP portfolioimplementation transmits data on the active link and transmits an idle signal on the inactivelink. The failure of the signal in either direction causes both near-end and far-end equipmentto switch to the protecting line. The Alcatel-Lucent implementation has the flexibility to allowthe working circuit of an APS group to be on one router and the protect circuit of the sameAPS group to be on another router.

4.6 Mitigating DoS AttacksDenial of service (DoS) attacks present an ongoing area of vulnerability for cable MSOstoday. The advanced architecture of the Alcatel-Lucent 7750 SR and 7450 ESS uses a two-stage approach to ensure that service levels will not be impacted by misbehaving or malicioususers (Figure 6).

Figure 6. Mitigating Denial of Service Attacks with Traffic Rate Limits

The service-aware architecture isolates traffic flows to ensure that incoming traffic is ratelimited, subject to access control list (ACL) classification, and queued based on fairness sothat one peer cannot consume all the system bandwidth.

In addition, for traffic destined to the CPM, CPM queuing eliminates the effect of one peerconsuming all the CPM resources (Figure 7). CPM queuing allocates hardware queues on apeer-to-peer basis. Each peer is then served on a round robin basis to further eliminate the effectof one peer consuming all the control complex CPU resources. These mechanisms help ensurethat misbehaving or malicious users will not affect other users.

ForwardingComplex

ForwardingComplex

CPUForwarding

Complex

SwitchTap

Traffic Flow

Traffic is rate limited and subject toACL classification with deny/permit action

SwitchFabric

SwitchTap

IOM CPM

SwitchTap

DoS

DoS

MDA

MDA

CPM-destined traffic is queued based onapplication, with fairness between applications

External traffic is subject to ACLclassification based on filter configuration

Per-application queuing is appliedto traffic flows sent to the CPM-CPU

12 Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

Figure 7. Mitigating Denial of Service Attacks with CPM Queuing

5 Service QoS: The Cornerstone of Service Velocity More than the availability of services, service reliability also encompasses the need to ensurethat each service meets end user performance expectations. This requires a properly dimen -sioned network to deal effectively with congestion during peak periods and the application of policy for added flexibility for session-oriented services. How well this is done can be animportant differentiator for cable MSOs.

To support the rapidly growing volumes of business-critical and delay-sensitive traffic, servicequality is necessary as a means of guaranteeing deterministic bandwidth. For an SME or largeenterprise to trust its operations to a business VPN over Ethernet or over the HFC network,that network must provide quality controls that are comparable to those available inconnection-oriented frame relay or ATM networks.

One of the defining attributes of the Alcatel-Lucent IP portfolio is its ability to meet individualservice quality requirements for all services traversing the IP/MPLS network.

5.1 Network and Service Capacity PlanningThe Alcatel-Lucent IP portfolio uses RSVP-TE and service-aware hierarchical QoS tofacilitate network and service capacity planning. Together, these mechanisms ensure thattraffic flows of all types can be prioritized and controlled across the network and that eachservice has the reliability and resources to meet customer performance expectations.

End-to-end service quality is guaranteed by creating bandwidth reserved LSPs using RSVP-TE.Static and signaled LSPs are supported and signaled LSPs can either be (loose or strict) explicitpath or constrained path. Up to eight backup LSPs can be configured on a RSVP-TE signaledLSP. In addition, the Alcatel-Lucent IP portfolio provides the ability to tunnel an LDP LSPinside an RSVP-TE LSP to create end-to-end LDP connectivity between multiple interiorgateway protocol (IGP) areas across a core MPLS network, without requiring a full mesh ofRSVP-TE LSPs between provider edge routers.

5.2 Service AwarenessThe Alcatel-Lucent IP portfolio implements leading service awareness to enable multi-serviceand multi-QoS SLAs to guarantee that QoS parameters on voice, video and data applicationscan be achieved, while simultaneously optimizing network resource utilization (Figure 8). Thiscombined capability enables the cable MSO to cater to the dynamic traffic patterns of video,multimedia and on-demand applications.

StandbyCPM

Ensures misbehavingor malicious users willnot affect other users

ActiveCPM

PeeringRouterIP/MPLS

Network

DoS

Services and SLAstraversing other peersremain unaffected

PeeringRouter

13Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

Figure 8. Service Velocity Enabled through Service-aware QoS

Service-aware QoS provides:• Up to eight forwarding classes per service, from high-priority to best-effort• Over 8000 ingress queues and 8000 egress queues per MDA• Queue buffering per MDA at an average of 200 ms of ingress and 200 ms of egress buffering

at 10 Gb/s• Support for tens of thousands of customers per system

Service-aware QoS coupled with RSVP-TE provides service-based queuing, policing and shaping,with per-service bandwidth guarantees to meet the most demanding SLAs — without the extracost of special modules for advanced features. Each service can use multiple queues to enableshaping, policing and marking of different flows or forwarding classes.

The Alcatel-Lucent IP portfolio can shape and police on service egress so customers can pur -chase sub-rate services (e.g., Internet access services) with asymmetric SLAs. Customer isolationis also inherent in the service-aware architecture of the Alcatel-Lucent IP portfolio, allowingfor the simultaneous support of Layer 2 and Layer 3 services while maintaining SLAs and per -formance levels for existing and emerging services. End-to-end network service quality can beguaranteed by creating bandwidth-reserved LSPs using RSVP-TE.

Alcatel-Lucent has extended the QoS feature set to apply QoS policies to LAG access ports.Additionally, the Alcatel-Lucent IP portfolio gives operators two user-selectable modes tomanage H-QoS policies when LAGs span different line cards. This allows the active LAGmember selection based on SLA enforcement constraints to ensure H-QoS is met while themaximum number of links is utilized.

The combination of traffic engineering mechanisms of MPLS with H-QoS on the service routerprovides cable MSOs flexible commercial strategies that allow them to maximize revenue withtimely services, while ensuring reliability meets quality requirements for newly provisionedresidential and commercial business customers.

DSCP=5=Voice

OverallSLA

=12 Mb/s

PIR=2 Mb/sCIR=2 Mb/s

PIR=2 Mb/sCIR=2 Mb/s

PIR=maxCIR=0

PIR=maxCIR=0

DSCP=4=Video

DSCP=1=Priority

DSCP=0=Normal

OverallSLA

=16 Mb/s

Multi-Service SLA

Multi-QoS SLA

7750 SR/7450 ESS

CIR: Committed Information RateDSCP: Differentiated Services Code PointPIR: Peak Information Rate

PIR=12 Mb/sCIR=2 Mb/s

GigE

PIR=maxCIR=0Internet Access

VPLS Service

Guaranteed, Deterministic Performance Residential and Commercial Customers

CMTS

Residential

Commercial

PON

14 Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

6 Service Management: Improving Operational EfficiencyTo ensure the long-term profitability of their business, cable MSOs must be able to introduceand maintain new services cost-effectively. One of the challenges they face in this process isto improve overall operational efficiencies by:• Improving activation time for new services from days to hours• Having a common view of the network to apply end-to-end policies and reduce the time

to identify and fix a service issue – from a central network operations center (NOC)• Provide commercial business customers with a better window to track or request changes

to their VPN service, anytime

Intelligent management applications that pro-actively identify potential network or serviceproblems or allow operators to quickly identify and resolve customer problems are essential in assuring service and network infrastructure reliability (Figure 9).

The Alcatel-Lucent 5620 SAM offers two powerful methods to satisfy these goals: the servicetest manager and service-aware fault management.

Figure 9. Problem Isolation Comparison

6.1 OAM TestsThe Alcatel-Lucent 5620 SAM STM orchestrates the generation of OAM tests for individualor groups of services, LSPs or routers. By specifying a suite of OAM tests, fail conditions formetrics such as latency, delay and packet loss, a schedule and a target test group, the 5620SAM test suite can regularly report on network and service health. It can also pro-activelygenerate threshold crossing alarms to alert operators when gradual or momentary SLA metricviolations are detected.

In addition to pro-actively monitoring SLAs, allowing 5620 SAM operators to pre-define agroup of OAM tests into an integrated test suite has a number of key benefits:• The operator can use the 5620 SAM to run an integrated test suite upon request, allowing

for quick diagnosis of faulty or mis-configured services and the underlying network layers.• When network topology changes, due to the addition of a new router or a new service site,

the 5620 SAM automatically generates additional tests to verify the new entities. • Operators or flowthrough operation support system (OSS) applications can verify a newly

activated service by trigger ing a test suite that automatically generates the necessary OAMtests and reports test results via an operational status flag.

• OSS performance management and customer portals can leverage pre-configured service testsuites instead of deducing the service topology and the appropriate OAM tests to triggerand parse individual test results. This assures services while reducing time-to-market andintegration costs.

Identify

Improve Restoration Time by 67%Reduced SLA Penalties

Fix

MTTR MTTR

Identify

Source: RHK-Ovum

Competitor Problem Isolation15 minutes

5620 SAM Problem Isolution5 minutes

Fix

15Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

In essence the 5620 SAM OAM tests generate a ‘birth certificate’ for network deployment thatcan characterize the underlying network and provide a baseline reference for the effect of futureservices on jitter, latency, and delay. This enables the cable MSO to quickly understand thedelta should performance issues afflict the network.

The 5620 SAM service-aware fault management capability offers comprehensive service faultmanagement, service impact analysis, root cause analysis and service topology map features toreduce MTTR and SLA penalties: • In addition to equipment and protocol alarms generated by the network elements, the 5620 SAM

generates service alarms after it has correlated which services are affected by the failure.• The service alarm provides a one click navigation option to affected customer information

and affected objects and states the cause, which provides the operator with the originalcause of service failure.

• The operator can also view the service topology and affected objects on a graphical user interface.

6.2 Timely Fault Isolation A lack of debugging tools hinders the ability to troubleshoot and minimize MTTR. The Alcatel-Lucent solution delivers a comprehensive suite of service-aware OAM tools. These tools allowoperators to quickly identify, isolate and troubleshoot service and network faults to minimizedowntime during planned and unplanned network events.

The Alcatel-Lucent IP portfolio equips operators with service level and network level OAMtools for rapid fault identification. In addition to support for standards such as IEEE 802.3ah,the comprehensive OAM toolkit includes:• Service level OAM tests:

¬ Service ping allows the operator to know if the service is provisioned accurately andprovides end-to-end connectivity testing for an individual service

¬ VPLS ping and trace route verify that the forwarding table is not the cause of connectivityissues and allows the operator to trace the path the packets take through the network

¬ VPRN ping and trace route verify that the forwarding table is not the cause of connectivityissues and allows the operator to trace the path the packets take through the network

¬ Virtual circuit connectivity verification (VCCV) ping checks the connectivity of a point-to-point VPWS

¬ Pseudo-wire status signaling provides end-to-end OAM status on manually switchedpseudo-wires to both service router endpoints

¬ Multiprotocol status signaling checks the status and provides a trace of Ethernet, framerelay and ATM pseudo-wire paths

¬ Service mirroring allows the operator to view a customer’s packet from a central locationas it traverses the network without the need for a costly sniffer overlay network

¬ Service assurance agent verifies the health and quality of SLA commitments by calculatingperformance metrics such as delay, jitter, loss, and by monitoring thresholds for potentialSLA violations

• Network level OAM tests:¬ LSP ping and trace route detect data plane failures in LSPs and connectivity in both direc -

tions by verifying whether the packet reaches the label edge router and provides the hop-by-hop destination path of the LSP

¬ Multicast troubleshooting tools (MRTrace, MStat, MRInfo) allow the operator to deter -mine where multicast flows stop, verify the flow of the multicast stream, show the multi -cast path in a graphic display and display multicast configuration information from aspecific multicast router

16 Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

In summary, the Alcatel-Lucent 5620 SAM provides the enhanced service provisioning andassurance capabilities that maximize the operations, administration, maintenance and provi -sioning (OAM&P) functions available in the service router (Figure 10). The OAM toolsenable cable MSOs to provide comprehensive fault management and assurance on a per-service basis with monitoring of performance metrics for latency, jitter and packet loss toprovide pro-active management of delay-sensitive applications. These tools enable the cableMSOs to test application flows in both directions for video, VoIP and business critical data,and thereby enable fast, accurate, efficient resolution of a customer’s service problems.

Figure 10. Ensuring Video, Voice and Business Data SLA Performance Metrics

In addition, with detailed performance metrics, cable MSOs can offer business customers web portals with the 5620 SAM customer toolkit, which can be used to provide reports thatdemonstrate how their SLAs were met over time and what level of performance their trafficactually experienced over the network. Portals can also enable business customers to changeQoS levels on one of their services or increase bandwidth when necessary. These types oftools help cable MSOs increase revenues.

7 ConclusionTo continue to offer competitive residential services and support ventures into the businessand wholesale market, cable MSOs must transform their networks to deliver converged con -sumer, business and mobile services. Therefore, the next generation of cable MSO networksmust effortlessly deliver multimedia and on-demand services with a high level of quality andservice assurance to all markets.

By consolidating services over a common IP/MPLS infrastructure, cable MSOs can successfullydeliver the services these diverse markets demand. But consolidation only addresses the deliverychallenge. To address service quality and reliability issues, cable MSOs must look beyond the

Customer A

Customer A

Customer B

Customer C

ResidentialServices

IP/MPLS 10 GbEOptical MetroRing Network

OAM Notification

SME and Large Enterprise

Hub

5620 SAM

7750 SR

Headend

Customer A

Commercial BusinessServicesLayer 3: IP-VPN

Service Assurance Test – Customer A

Layer 2: VPLS & VLL

7750 SR7450 ESS

OAM toolkit for rapid troubleshootingon a per-service basis

Fast service activation and faultnotification Customer Web portal

Maintain SLA performance metrics. Testservice latency, jitter, packet loss andround-trip delay from a central NOC

CMTS

EQAM

D2AVideoServer

AdInsertion

17Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

underlying infrastructure to the routers that route services through their networks. Those routersmust be advanced, service-aware platforms designed from the ground up to guarantee the high -est levels of service availability and service quality from hardware and software architectures.In addition, service management must be tightly integrated with these service routers to ensureongoing service reliability and minimize operational costs.

Alcatel-Lucent offers industry-leading routing solutions that have been engineered from theground up for service quality and reliability (Figure 11).

Figure 11. Converged, Service-Aware IP/MPLS Network Architecture for Cable

With this complete approach, cable MSOs can count on their networks to meet the highestquality of experience requirements necessary to deliver the new wave of next generationvideo and IP-based services to residential and commercial business customers.

IP/MPLS10 GbE

VoDand AdServers

Regional Headend

DigitalSource

AnalogSource

IP/MPLS 10 GbEMetro Transport Network

ManagedBusiness

Applications

VoiceGateway

7750 SR

BMR(Video Proc)

Analog

Analog

GigE

E-LAN (VPLS) & E-Line (PWE3)

M

OA

M/R

F

I

LocalBroadcaster

LocalVenues

HSI

VoD andAd Servers

Distribution Hub

7750 SR/7450 ESS

BMR

BME (EQAM)

CUDA(M/I-CMTS)

SBSS

Decoder/z-Mod

Commercial

Residential

WirelessBackhaul

RF

VoD andAd Servers Distribution Hub

BMR

7750 SR

Commercial

Commercial(Carrier Ethernet)

Residential

WirelessBackhaul

HFC

GPON

National BackboneNetwork (IP/ MPLS)

RegionalHeadend

Decoder/z-Mod

7342 P-OLT

V-OLT

7750 SR7450 ESS

RF

WDM

MDU

Layer 3 – IP-VPN

WirelessBackhaul

7342 ONT

Alcatel-Lucent | Converged, Service-aware IP/MPLS Network Architecture for Cable MSOs1818 Alcatel-Lucent | Converged, Service-Aware IP/MPLS Network Architecture for Cable MSOs

8 Acronyms

ACL Access control list

APS Automatic protection switching

ARPU Average revenue per user

BGP Border gateway protocol

BFD Bidirectional forward detection

CMA Compact media adapters

CPM Control processor module

DOCSIS Data over cable service interface specifications

DoS Denial of service

FEC Forward equivalency class

FRR Fast reroute

HFC Hybrid fiber coax

IGMP Internet group management protocol

IGP Interior gateway protocol

IMS IP multimedia system

IOM Input output module

IS-IS Intermediate system to intermediate system

ISSU In-service software upgrades

LAG Link aggregation group

LDP Label distribution protocol

LSP Label switched path

M-CMTS Modular cable modem termination systems

MDA Media dependant adapters

MEF Metro Ethernet Forum

MPLS Multiprotocol label switching

MSO Multiple service operator

MTTR Mean time to repair

NOC Network operations center

OAM Operations, administration and maintenance

OAM&P Operations, administration, maintenance and provisioning

OCAP Open cable applications platform

OPEX Operating expenditures

OSPF Open shortest path first

PIM Protocol independent multicast

PIM-SM Protocol independent multicast-sparse mode

QAM Quadrature amplitude modulation

QoE Quality of experience

RSVP-TE Resource reservation protocol — trafficextension

RIP Routing information protocol

SIP Session initiated protocol

SLA Service level agreement

SME Small-medium enterprise

SOA Service-oriented architectures

SSC Subscriber services controller

VCCV Virtual circuit connectivity verification

VLL Virtual leased line

VoD Video on demand

VoIP Voice over IP

VPLS Virtual private LAN service

VPWS Virtual private wire service

VRRP Virtual router redundancy protocol

VXML Voice extensible markup language

WAN Wide area network

XML Extensible markup language

www.alcatel-lucent.comAlcatel, Lucent, Alcatel-Lucent and Alcatel-Lucent logo are trademarks of Alcatel-Lucent. All othertrademarks are the property of their respective owners. The information presented is subject to change without notice. Alcatel-Lucent assumes no responsibility for inaccuracies contained herein.© 2007 Alcatel-Lucent. All rights reserved. 21908 (07)