atm ip migration en appnote
TRANSCRIPT
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A P P L I C A T I O N N O T E
Legacy ATM Migration to IP/EthernetLeveraging the 7705 SAR for Wireline Transformation
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Abstract
As Internet usage is growing signicantly due to an insatiable appetite or multimedia applicationsand content, many operators are acing an increasing amount o legacy obsolescence issues withtheir installed base o high-speed Internet inrastructure. What was a strategic asset just a ew yearsago has suddenly turned into a nancial liability that is limiting service growth and innovation.
A majority o these service providers may already have considerable investments in next-generationbroadband inrastructure based on IP, Ethernet and MPLS technologies, but lack the critical linkthat provides backwards compatibility with their legacy ATM-based inrastructure. As a result,many existing subscribers, services and revenues are eectively marooned on an island o legacyinrastructure that is acing rapidly dwindling resources.
The Alcatel-Lucent 7705 Service Aggregation Router (SAR) is a next-generation aggregation platormthat is purpose-built or network transormation tasks spanning TDM, ATM, Ethernet and IP/MPLStechnologies. The Alcatel-Lucent 7705 SAR bridges technology generation gaps between evolving2G, 3G and 4G mobile networking technologies just as easily as it can bridge those that existbetween TR-059 and TR-101 broadband aggregation networks or wireline.
This application note discusses the application o the 7705 SAR to enable operators to cost-eectivelyleverage and consolidate their existing ATM DSLAM installations on a next-generation IP/Ethernetbroadband services platorm.
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Table of contents
1 1. Executive summary
2 2. New technology introduction and legacy migration
3 3. Alcatel-Lucent 7705 Service Aggregation Router
4 4. Legacy aggregation and interworking scenarios
5 4.1 Legacy ATM transport over MPLS pseudowires
6 4.2 Legacy ATM interworking with Ethernet aggregation
9 5. Legacy subscriber consolidation and service innovation
11 6. Alcatel-Lucent data integration and migration services
11 6.1 Multivendor Integration
13 6.2 Multivendor data network migration
14 7. Conclusion
14 8. References and sources
14 9. Glossary of terms
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Legacy ATM Migration to IP/Ethernet | Application Note 1
1. Executive summary
The introductions o IPTV, video on demand (VoD) and rich multimedia services require a networktransormation rom todays IP service delivery networks that are built or best-eort Internet (HSI)services to a converged, uture-sae broadband services platorm that is able to take on Web 2.0delivery requirements.
The main rationale or an HSI legacy migration is to shit investments rom legacy maintenance tothe strategic build-out o next-generation inrastructure and services. Although legacy inrastructurerepresents a sunk cost and is ully operationalized, there are increasing and ongoing maintenanceexpenses (i.e., OpEx), while the network lacks the capacity and capability or service innovationand new revenue creation.
Although legacy network migration is needed, the goal is to make such migration nancially easibleand operationally non-disruptive. A lot o time and resources have gone into the establishment oexisting IT/OSS inrastructure and this eort should be leveraged by providing backwards compat-ibility with the present mode o operation, while paving the way towards a uture mode o operation.A gradual migration o the IP transport layer rom legacy ATM to Ethernet and rom PPPoX toIPoE eases the migration o existing subscribers and services to the next-generation all-IP platorm.
This application note reviews a subset o migration scenarios that are based on best practices thathave been developed with leading service providers to address these migration requirements in acost-optimized manner (see Figure 1).
Figr 1. Lgacy radad twrk trasfrati
Transport IT/OSS
Service migration
CPE
CPE
DSLAM
AN EAN
Policy Manager
RADIUS/DHCPserver
ConvergedOSS Apps
Multiple devicesper subscriber
BNG
LegacyBRAS
RADIUSserver
Billingsystem
ATMaggregation
Next-gen TR-101 network
Legacy PPoE HSI network
HQoS
PPPoEDiminishing
network value Cash cow
Strategicnetwork value Investment
phase
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2. New technology introduction and legacy migration
As the legacy HSI inrastructure and service models are being challenged by the rise o Internetvideo, on-line gaming and other rich multimedia content, an infection point is approaching atwhich it becomes more economical to transorm the network to a new architecture that is betteroptimized to handle these requirements than to keep progressing with incremental legacy upgrades.
For many Telco service providers, this network transormation was triggered by the need to oer IPTVas a means to close an important gap with competing MSOs in terms o services portolio. For others,this transormation point only occurs now, as their legacy HSI inrastructure is becoming increasinglycongested by emerging, bandwidth-hungry applications like peer-to-peer and streaming video.
From a cost and investment perspective, the goal is to balance the cost o rolling out new inrastruc-ture, and to address multimedia service innovation requirements, while at the same time avoidingthe need to make substantial upgrades and extensions o the installed base to cater or continuinggrowth in HSI in other words how to implement an eective cap-and-grow strategy that lever-ages installed base assets, while reaching the end-goal o converged service delivery?This migration will take several years to complete, and it is thereore important to manage capital
and operational expenditures during the transormation process careully, as well as absorbing theramp-up costs o building a next-generation service delivery inrastructure, while saving cost orlegacy services and inrastructure. The transormation process has the ollowing phases:
Introductionphase: The initial roll-out o a next-gen residential IP broadband inrastructure,to build service coverage in a given geographical area, in conjunction with legacy voice andHSI networks.
Upgradephase: This is a cap-and-grow phase in which the next-gen inrastructure provides ullservice coverage in a given area. Both new subscribers and existing voice and HSI subscribersthat upgrade to a multiservice bundle are migrated over to the new all-IP broadband networkin a gradual process. (This is indicated by the vertical arrows dropping down in Figure 2.)
Migrationphase: Legacy inrastructure is being phased out and remaining customers are transpar-
ently migrated to the next-gen inrastructure, even i they have decided not to upgrade theirexisting service. The rationale is to reduce the cost o maintaining separate legacy inrastructuresin parallel. (This is indicated by the horizontal arrows in Figure 2.)
Figr 2. All-IP radad twrk trasfrati prcss
Legacy PSTNDialup IA
Legacy HSIA
CAPEX/OPEXrequirements
POTS
Best effortservices
Triple Play bundles
Introduction
IPTV/videoinflection point
HDTV/PIP VoD/nPVR
Connectedhome
Multiscreenmultimedia
All-IP NGN
Internet video On-line gaming
Hybrid phone
IPTV
Time
MOS
VoIP/FMC
HSI migration
Internet videoinflection point
PSTN migration Converged services network
IP multimediainflection point
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Legacy ATM Migration to IP/Ethernet | Application Note 3
The end result is converged broadband service delivery over a common IP broadband inrastructure.Note that these phases may overlap in time, especially on a network-wide basis. While subscribersthat only require HSI and/or voice could still be served through the legacy ATM DSL access inra-structure, a legacy replacement o the ATM aggregation layer may be more cost-eective and uture-sae than to continue down the route o incremental upgrades.
The ollowing section will introduce the Alcatel-Lucent 7705 SAR as a platorm o choice to mi-
grate ATM legacy aggregation.
3. Alcatel-Lucent 7705 Service Aggregation Router
The Alcatel-Lucent 7705 Service Aggregation Router (SAR) is an edge aggregation platorm provid-ing superior IP/MPLS and pseudowire capabilities (Figure 3). The 7705 SAR excels at concentratingtrac rom wireline and radio access sites and adapting it to a normalized IP/MPLS inrastructure thatleverages available media, especially scalable, cost-eective Ethernet. It is also extremely eective attransporting o legacy trac such as T1/E1 private line transport over a modernized inrastructure.
Figr 3. Alcatl-Lct 7705 SAR faily
The 7705 SARs quality o service, trac management, provisioning, troubleshooting and billingeatures make it possible to provide consistent, superior services. Its fexible interace options (Figure 4)and uture-proo architecture will enable it to address evolving aggregation requirements.
Figr 4. Itrfac adaptr cards fr 7705 SAR-8 ad SAR-18
Built on the same architectural sotware base as the highly successul Alcatel-Lucent service routerproducts, the 7705 SAR enables the creation o an end-to-end solution or the growing xed andmobile aggregation market. The Alcatel-Lucent 7705 SAR backhaul solution employs pseudowireencapsulation methods to map services end-to-end, ensuring that the key service attributes are
7705 SAR-187705 SAR-87705 SAR-F140 Gb/s HD
Large aggregation hubs orsmaller central sites
4x 10Gadapter slots
12 Gb/s HD
Small to medium aggregation sites2 Gb/s HD
Small sites hardened
Alarm module
RedundantCSMs
12x 2.5Gadapter slots
8-port Ethernet: 6 ports of 10/100 Base-Tx 2 ports of 10/100/1000
with small form factorpluggable (SFP) optics
Ethernet 4-port OC-3/STM-1
clear channel 2-port OC-3/STM-1
channelized
SONET/SDH 16-port ASAP T1/E1 32-port ASAP T1/E1 4-port DS3/E3
ASAP
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maintained, while using a cost-eective packet environment to aggregate services. In addition topseudowire transport, IP routing and orwarding are supported. Services such as ATM, ATM IMA,Ethernet and TDM trac can be natively switched across the 7705 SAR and transported overEthernet/MPLS and SDH/SONET transport architectures.
Table 1 lists the key deployment benets o the 7705 SAR.
Tal 1. Ky dplyt fits
CuSTomeR ISSue oR PRobLem SoLuTIon DIFFeRenTIATIon
ATM switches were traditionally used forDSLAM aggregation, but broadband accessand services have now converged on IPover Ethernet transport
7705 SAR addresses the balance betweenleveraging existing investment in ATMDSLAMs while allowing for a transitionto Ethernet uplinks
The 7705 SAR has a unique transformationalcapability as it is a modern, compactIP/MPLS-based platform with legacyinterface support
Uplink capacity becomes a bottle neck, butupgrading the ATM infrastructure is not astrategic investment for the operator
Allows the operator to make the bestuse of the scalable Ethernet aggregationinfrastructure
The 7705 SAR provides high-densitycapacity from 2 to 140 Gb/s switchingcapacity in a compact chassis
Operator wants to leverage sunk investmentin ATM DSLAMs but has future-orientedinfrastructure in networking
7705 SAR can interconnect legacy ATMDSLAMs and IP DSLAMs over next genera-tion Ethernet and MPLS transport
The 7705 SAR allows full leverage ofexisting assets while investing for afuture-oriented architecture
4. Legacy aggregation and interworking scenarios
Today, ATM DSLAMs are deployed in the wiring oces (WO) and central oces (CO) o carriernetworks. The trac is aggregated by an ATM switch and then transported over a SONET networkto a central location where the BRAS terminates the sessions. But as trac volumes are growingdue to bandwidth-hungry Internet applications, operators are orced to deal with their ATM aggre-gation node congestion by building out capacity in the ATM and SONET network until there is acost-eective way to move the trac to the metro Ethernet network (see Figure 5).
Figr 5. Cxistc f lgacy ad xt-grati ifrastrctr
IP/MPLS Metro
SONET/ATM network
7750 SR
7750 SR
OC-3
OC-3
OC-3
DS3
N x T1
Ethernet
WO CO
ATM
DSLAM
ATM
DSLAMATM
switch ADM
ADM
ADM
7450 ESS
7450 ESSIP
BRAS
ATM
DSLAM
ATM
DSLAM
IP
DSLAM
IP
BRAS
Ethernet
ADM
ADM
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Legacy ATM Migration to IP/Ethernet | Application Note 5
While the legacy ATM network and the next-generation inrastructure can coexist and operate asships in the night, there is a signicant duplication o resources and eorts. Over time, a naturalsubscriber migration occurs as more demanding subscribers will upgrade their broadband service totypically higher speeds and a broader service oering that can be supported on the next-generationinrastructure. As the legacy inrastructure is gradually bleeding subscribers and revenues, it willultimately reach the point where legacy retirement becomes nancially attractive to the networkprovider. The question then is How do you conduct this retirement process in an orderly manner?
4.1 Legacy ATM transport over MPLS pseudowires
Service providers will look or a cost-eective migration strategy or legacy inrastructure that mini-mizes service disruption or the existing subscriber base. They will attempt to leverage the installedATM DSLAM base or existing customers, while minimizing expenditures on urther capacityupgrades to cater to increasing HSI trac volumes. The validity o the DSLAM upgrade scenarioswill depend on the make, model and age o the installed base. One option is to upgrade existingATM DSLAMs (e.g., Alcatel 7300/7301 ASAM) with Ethernet network terminations, eectivelyturning them into IP DSLAMs that can directly interace with a next-generation aggregation network.However, this eectively entails an investment in legacy inrastructure, which may not be the bestuse o capital.
The alternative is to use legacy interacing options in the next-generation aggregation network. Inthis scenario, the Alcatel-Lucent 7705 SAR is introduced to directly aggregate trac rom legacyATM DSLAMs typically rom N x T1, DS3 and OC-3 uplinks that are carried within ATM VPs and encapsulate this trac in MPLS tunnels or transport over the IP/MPLS or SDH/SONETmetro network.
Subscriber trac rom IP DSLAMs in the same CO can be aggregated on the same 7705 SARthat provides investment protection in the aggregation layer, as subscribers and services graduallymigrate rom legacy ATM DLSAMs to IP DSLAMs.
The solution (see Figure 6) replaces the existing ATM aggregation network, which can then bephased out. To manage subscriber services delivered rom the legacy ATM DSLAMs, there aretwo options:
Adual-edgeapproach,inwhichlegacyATMBRASandnext-genIPBRAScoexist.TheATMBRAS is managing subscribers on the legacy ATM DSLAMs, and the IP BRAS is handling IPDSLAM subs. The 7750 SR acts as the L2 service edge, handing subscriber trac to respectivelegacy ATM BRAS and IP BRAS systems. The advantage is a transparent operational migrationo the legacy ATM aggregation layer in which the existing ATM BRAS is ully leveraged.
Asingle-edgeapproach,inwhichinterworkingfunctionsadaptsubscribertrafcfromATMDSLAMs or termination on an IP BRAS in order to phase out legacy ATM BRAS. In thisscenario, the 7750 SR can act as a converged Broadband Network Gateway or all subscribers,thus avoiding the need or separate BRAS systems. The advantage is a more consolidatednetwork and a more homogeneous subscriber experience.
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Legacy ATM Migration to IP/Ethernet | Application Note6
Figr 6. Aggrgatig lgacy ATm PVCs it ATm VPs vr mPLS psdwirs
Note that these scenarios are not necessarily competing alternatives. They can be executed sequentiallyas a migration strategy that, rst, consolidates legacy ATM DSLAMs in a common aggregationnetwork and, secondly, consolidates legacy subscribers and services on a converged IP service edge.Conducting the migration in two steps may spread the amount o complexity and eort involved.The 7705 SAR can aggregate trac both on a next-generation MPLS/Ethernet metropolitan areanetwork or existing SDH/SONET metro transport networks.
4.2 Legacy ATM interworking with Ethernet aggregationThe advantage o transporting ATM trac over MPLS pseudowires lies in its operational simplicityand interworking transparency. Subscribers and services delivered rom legacy ATM DSLAMs sharethe same aggregation network but peaceully coexist and operate as ships-in-the-night. The drawbacko this scenario is that this logical separation implies the need to maintain a redundant operationalinrastructure or legacy and next-generation services, which may be costly over time.
The ollowing aggregation scenario remedies this issue by introducing interworking unctions in theaggregation layer, which allows or the adaptation o subscriber trac rom legacy ATM access tracinto a next- generation IP/Ethernet environment, and subsequently on a common IP service edge.
The interworking scenario (Figure 7) aggregates ATM Virtual Private Connections into Service
Access Points (SAPs) on a Virtual Private LAN Service. This solution is available or the 7705 SARin R 4.0 and is identical to the way IP trac is aggregated in the Alcatel-Lucent Triple Play ServiceDelivery Architecture model using Virtual Private LAN Services (VPLS) to aggregate subscriber trac.
IP/MPLS
Metro
7750 SR(BNG)
ATM VP pseudowire
OC-3
OC-3
DS3
N x T1
WO CO
ATM
DSLAM
ATM
DSLAM
7705
SAR-18
GigE
7450 ESS
7450 ESS
GigE ATMBRAS
ATM PVC
MPLS
PPPEthVCIVPI
Srvc LblMPLS Lbl
PPPEthVCIVPI
PPPEthVCI
VPI Srvc LblMPLS Lbl
IP
BRAS
ATM
DSLAM
ATM
DSLAM
IP
DSLAM
ATM broadband
services
IP broadband
services
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Figr 7. Aggrgati lgacy ATm PVCs i ethrt Virtal Privat LAn Srvics
A logical bridging domain (VPLS) is created, which can terminate ATM Permanent VirtualConnections (PVCs). Each ATM PVC is attached as a circuit into the VPLS instance, andsubscribers are represented as residential Service Access Points (SAP) towards the 7450 ESS/7750 SR. The SAPs will take PPPoEoA or IPoEoA trac coming rom the CPE/DSLAM andremove the ATM encapsulation to expose the Ethernet header. VPI/VCI addresses are associatedto MAC addresses in the Ethernet domain and QoS is applied. For reliability reasons, the VPLSinstance utilizes redundant uplinks. Split Horizon orwarding prevents trac exchange between
attached circuits or security reasons (Figure 8).
The advantage o the interworkingscenario based on subscriber SAPs isthat it ts into the 7450 ESS/7750 SRmanagement paradigm in a similarway as subscribers on an IP DSLAMwould. It also provides an easy wayto map subscriber trac rom SAPson other types o Layer 2 and Layer 3identiers at egress o the MPLScloud, in order to adapt to dierentBRAS interworking requirementsor dierent wholesale/retail demar-cation options.
IP/MPLS
Metro
7750 SR(BNG)
7750 SR
7750 SR
Spoke SDP to ePipe service
OC-3
OC-3
DS3
N x T1
WO CO
ATM
DSLAM
ATM
DSLAM
7705
SAR-18
GigE
7450 ESS
7450 ESS
GigE
ATM PVC
MPLS
ATM
DSLAM
ATM
DSLAM
IP
DSLAM
ATM and IP
broadband services
ATM residential
SAP and VPLS
Figr 8. Rsidtial Split Hriz
Split horizon
ATM
ATM
ATM
ATM
ATM
GigE
GigE
Redundantuplinks
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An alternative to using residential SAPs or mapping subscriber trac is shown in Figure 9 and isusing MPLS uplinks to groom trac to the IP service edge (7750 SR). MPLS uplinks can be initiatedat the 7705 SAR or at the edge o the Ethernet aggregation network, depending on operationalrequirements. There are two options (A and B) or extending the MPLS uplinks:
OptionAextendsMPLSallthewaytothe7705SAR.Inthiscase,MPLSfastrerouteisusedtoprotect uplink resiliency on the 7705 SAR. This option works well with centralized subscribermanagement on the 7750 SR (routed CO), or on BRAS systems attached to it. C-VLAN tags
are dened per VP/VC on a SAP basis and pushed on access ingress at the 7705 SAR. TheS-VLAN tag can (optionally) be pushed in the 7705 SAR and dened per spoke SDP or theVPLS service. The S-VLAN can also be pushed by the 7750 SR on access egress toward theEthernet BRAS (i required).
A consequence o using this option is that there is no possibility or IGMP snooping unctionsin combination with IP multicast distribution. This capability is used or IPTV service deliveryto intelligently orward only those channels that are actually being watched by attached sub-scribers. This is typically not an issue when aggregating subscribers rom legacy ATM DLSAMsbecause these access nodes generally lack the capacity to deliver IPTV service. However, orattached IP DSLAMs this is a consideration.
OptionBinitiatestheMPLStunnelsattheedgeoftheEthernetaggregationnetwork.Inthis
case, Gigabit Ethernet Link Aggregation Groups (LAG) are being used to enable resilient uplinkconnectivity between the 7705 SAR and the 7x50. This scenario allows the 7x50 to enableIGMP snooping (i.e., VPN multicast registration) or ecient IPTV channel distribution andalso allows distributed subscriber management on the 7x50. The 7705 SAR tags subscriber tracwith both S and C-VLAN tags so that at egress o the MPLS cloud no urther VLAN-taggingis required.
Figr 9. ATm t ethrt itrwrkig sig mPLS pliks
To support Lawul Intercept requirements, PPP PADI/PADO messages are captured at access ingresso the 7705 SAR upon which an Agent-Circuit-ID TLV can be inserted or interception and sourcetrace at the BRAS. As beore the 7750 SR can either act as converged Broadband Network Gateway,combining IP Service edge and subscriber management capabilities, or act as a Broadband ServiceRouter eeding into separate BRAS systems.
MPLS (Option B)
MPLSnetwork
ATM
DSLAM
7705 SAR
STM-1
GigE/10GigE
PPP
Eth
ATM
PPP
Eth
C-VLAN
VPLS Lbl
MPLS Lbl
PPP
VoIP
BRAS
Eth
C-VLAN
VPLS Lbl
MPLS Lbl
PPP
Eth
C-VLAN
CPE VC: VoiceVC: Data
VLAN translation
GBE
7750 SR
GBE
7x50
7x50
MPLS (Option A)
MPLS (Option A)
CO
PPPEth
C-VLAN
S-VLAN
MPLS(Option B)
Push S-VLAN@ Service Egress
No pushrequired
PPPEth
C-VLAN
S-VLAN
VPLS Lbl
MPLS Lbl
PPPEth
C-VLAN
S-VLAN
PPP
Eth
C-VLAN
S-VLAN
VPLS Lbl
MPLS Lbl
HSI
BRAS
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In conclusion, the Alcatel-Lucent 7705 SAR provides several options to aggregate and transportsubscriber trac rom legacy ATM DSLAMs into an Ethernet/MPLS based broadband inrastructure.Which option is best depends on operational requirements expressed by the service provider. Alcatel-Lucent recommends conducting a network architecture review to determine the best option orward.
The Alcatel-Lucent 7705 SAR is IPv6 ready, even as the use o IPv6 is transparent in the specicLayer 2 aggregation applications described in this paper. IPv6 and dual stack subscriber management
are an important requirement or the BNG though and the 7750 SR is ully compliant in this area.
In addition to migrating the legacy ATM aggregation network, there are various options or consolidatingsubscriber trac rom legacy ATM DSLAMs and IP DSLAMs on a converged Broadband NetworkGateway. This is the subject o the ollowing section.
5. Legacy subscriber consolidation and service innovation
The introduction o the Alcatel-Lucent 7705 Service Aggregation Router provides an elegant andcost-eective solution to enable service providers to shit investments rom legacy ATM aggregation(and optionally SDH/SONET) to a more strategic and long term investment in next-generationbroadband aggregation inrastructure. However, urther research will likely point out that the legacy
subscriber services edge ( i.e., BRAS system) is also approaching the end o its technical and economicallie cycle and in need o replacement.
This discussion revolves around IP edge convergence on a Broadband Network Gateway (BNG)as dened in the TR-101 architecture standard by the Broadband Forum or multiservice deliveryto residential consumers (see Figure 10).
Figr 10. Th bnG i th TR-101 architctr fr ethrt-asd DSL aggrgati
There are several motivations that drive service providers towards a consolidation o these variousservice edges into a single converged IP edge centered on the BNG. The rst motivation is legacyobsolescence: Many BRAS deployments are reaching their end-o-lie, both technically and eco-nomically. Some products are already manuacturer discontinued; others simply do not have thehorsepower or headroom to take on new requirements or rich multimedia content delivery andIPv6, and a replacement is needed.
A10-NSP
L2TP
IP-QoS
IP-QoS
Regional broadbandnetwork
Access network
Aggregation network
Customer prem. net.
A10-NSP
A10-NSP
A10-ASP
V
T
V
NSP/BBnetworkgateway
NSP2
ASP1
NSP1 L2TS
IP
Ethernetaggregation
Accessnode
(DSLAM)
Accessloop
MDF NID
User1
CPE
User2
BBnetworkgateway
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Besides obsolescence issues with legacy BRAS systems, there are more overarching concerns toreduce complexity and cost, both capital and operational expenditures. Network elements thatperorm the role o subscriber and/or service edge are the most complex and heavily instrumentedsystems in a network. Thereore, i one can consolidate the amount o edge unctionalities on ewerplatorms, or ideally only on one platorm, there can be signicant cost synergies. A convergedservice edge also makes it ar easier to oer a seamless multi-screen service experience to theconnected home.
Consolidating subscriber trac rom both legacy ATM DSLAMs and next-gen IP DSLAMs ona common Broadband Network Gateway will provide a more consistent service behavior acrossdierent access modalities and lower the operational threshold and eort involved in migratingsubscribers rom ATM to IP DSLAMs, in order to benet rom superior bandwidth and innovativeservice options. A common BNG approach creates easy up-sell opportunities to existing consumerswith the least amount o administrative overhead. Such IP service edge consolidation can be obtainedin various manners with dual- or single-edge implementation models (see Figure 11).
Converging on a single IP edge yieldsthe largest consolidation benets andwould result in a single touch point
with the network or all subscriberservices. To implement the single-edge BNG strategy, there is a choicebetween a distributed or centralizeddeployment model:
Thedistributed BNG model oersgood scalability and moves thesubscriber management pointcloser to end users, which isbenecial or peer-to-peer tracmanagement and allows orcaching and insertion o popularcontent that is closer to end usersthan what a centralized BNGmodel allows.
Thecentralized BNG model placeshigher scaling requirements onthe BNG itsel but may be advan-tageous in less densely populatedareas or or a dual-edge strategy(e.g., the HSI/VoIP edge couldpotentially be more centralizedthan a video or multiservice BNG).
When consolidating multiple serviceedges in the BNG, any existing Layer 2/Layer 3 overlay service models withseparate Layer 2 and Layer 3 edges caneither remain as they are, or can be consolidated urther by having a converged BNG with integratedLayer 2 aggregation. Whether this is easible and desirable will largely depend on the capabilities othe BNG platorm o choice and the preerences o the operational support organization.
Figr 11. Srvic dg cslidati
HSI edge
VoIP edge
Video edge
Ethernetaggregation
AA/DPI
Today
Goal
AN
HSI edge
Video edge
Ethernetaggregation
Dual edge
AN
Usually deployed in more distributed way
Converged andintegrated BNG
Ethernetaggregation
Single edge
AN
Usually deployed in more distributed way
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The Alcatel-Lucent 7750 Service Router is a TR-101 standard-compliant BNG that can operateas an integrated Layer 2/Layer 3 edge or as a Layer 3 edge in combination with the Alcatel-Lucent7450 Ethernet Service Switch as the L2 edge.
Besides oering ull compliance with TR-101 architecture requirements, deploying the Alcatel-Lucent7750 SR as a BNG oers a number o additional benets:
FullybackwardscompatiblesupportforTR-059BRASfunctionsbasedonPPPandL2TPas
Layer 2 Aggregation Concentrator, Layer 2 Tunnel Switch (L2TS) and/or Layer 2 NetworkServer (L2NS)
IPv6anddual-stacksubscribermanagementwithLargeScaleNetworkAddressTranslation
Fullsuiteofnetworkandservicemanagementsupportproductssuchasthe5580HomeNetworkManager, 5620 Service Aware Manager and 5750 Subscriber Services Controller
AnexperiencedprofessionalservicesorganizationtoassistintheIPnetworktransformation.
Expandingchoicewithmanagedonlineservicesforresidentialconsumersandcontentpartnersby leveraging Application Assurance technology to enable a premium Quality o Experienceor Internet video, audio, voice, gaming and other value-added content
OffersecureremoteVPNaccessovertheInternetbymeansoftheIPSecIntegratedService
Adapter (Besides being attractive or business users, this is also applicable to scenarios suchas mobile aggregation over virtual leased lines)
ComplementaryofferingofLayer2andLayer3VLLandVPNservicesforbusinessconsumersto maximize economies o scale o the broadband access and aggregation network
For the interested reader, there is a separate application note (need title o document) availablethat describes the deployment capabilities o the Alcatel-Lucent 7750 SR as multiservice BroadbandNetwork Gateway. In addition the Isocore Internetwork Lab recently conducted an independentvalidation o the entire BNG eature set o the 7750 SR. Alcatel-Lucent Residential Service DeliverySolution Verication is available on request.
6. Alcatel-Lucent data integration and migration services
Aside rom the underlying network platorm changes, service providers have overriding concernso an operational nature. First o all, there is a learning curve in mastering new technologies andplatorms. Then there is the operational eort o turning up these new platorms and subsequentlymigrating over the subscribers and services. Meanwhile business must go on as usual, 24/7.
Many service providers have adopted a lean operational model that is sucient to maintain day-to-day operations, but potentially challenged when having to absorb the transient peak workloadincurred by transormation. These are cases where Alcatel-Lucent Services can lead the integrationand migration project, thus providing an eective solution to manage the eort and risk involvedwith realizing an integrated, end-to-end solution. Alcatel-Lucent provides these services or its ownplatorms and or those platorms that are integrated in the equipment o many other vendors.
6.1 Multivendor Integration
Multivendor network integration encompasses design, integration, interoperability testing, solutionvalidation, and migration o IP/MPLS deployments, or telecommunication operators. The integrationservice philosophy is based on the operational reality that service providers operate platorms rommultiple vendors. These platorms must interwork with the Alcatel-Lucent solution beore and atermigration (Error! Reerence source not ound.).
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Legacy ATM Migration to IP/Ethernet | Application Note12
Figr 12. Alcatl-Lct ltivdr twrk itgrati
The multivendor integration services include Alcatel-Lucents industry-proven services ramework,planning and delivery tools, and access to our global centers o excellence. These assets have maxi-mized telecommunications operators capital investments in over 70 major IP/MPLS transormation
projects including many that utilize Alcatel-Lucent 7705 SARs and 7750 SRs. Results reaped by ourcustomer partners are deployment cost reductions o up to 60% and, in some cases, reduced projectcompletion times by several years.
Figr 13. Prfrac charks
IP/MPLSBackbone
Optical core
OpticalTransport
IP
Communications
Broadband
Internet
services
Personalized
IPTV
Residential
Enterprise
Copper,fiber
Mobile
Access
Centralized policymanagement
Aggregation
Multivendor
integration areas
IP ServiceEdge
Network and servicemanagement
Capability preparation Multiple years < 1 year
Multivendor data networkmigration services
Industryperformance
With Alcatel-Lucentinvolvement
Data and telecom specifictransformation methodologies
Minimal Over 70 IPtransformations
Typical delivery costs 100% Reduced by ~60%
Migration operation centers 0 2
IP transformation centers 0 4
Major IP/MPLS and VoIP/IMS migrations Minimal Over 100 countries
Risk All internal/wholly responsible Shared with Alcatel-Lucent
Transformation
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6.2 Multivendor data network migration
Successul data network migration is essential to many projects in order to meet their primarybusiness objectives. Achieving success requires careul planning and a detailed understanding oboth the legacy solution and the target solution. Figure 13 highlights the importance o migrationplanning and the creation o teams, processes, and tools to eectively acilitate mass scale changes.In most network transormation projects, there will usually be an objective to retire the legacy solu-tion as soon as possible, once the new solution is in place. While the two solutions are operating in
parallel, the operator has the increased burden both nancially and technically o having tosupport both platorms. Retirement o the legacy platorms can only occur when all o the custom-ers and services have been migrated to the new solution.
The objective o the Data Network Migration Services program is to deliver a complete end-to-endmigration solution to ensure success (see Error! Reerence source not ound.). Migration expertswork with service provider sta to develop the necessary support tools and procedures to migratethe customers and/or services (including all eatures) rom one technology platorm to another.All aspects o the migration process is controlled by the dedicated Migration Project Managementunction, which is responsible or specic management and reposting aspects related to migrationplanning, preparation and execution.
Figr 14. Alcatl-Lct Data ntwrk migrati Srvics
The Alcatel-Lucent migration methodology and processes, proven in data and voice migrationengagements in over 100 countries, ensures a structured approach to the design and delivery o themigration program. Alcatel-Lucent is also capable o providing a complete execution and supervisionservice through its Migration Operations Center a ocused team and acility that manages migra-tions 24/7. The center is able to handle migrations in any locale during any maintenance window,and work with legacy ATM, FR, DSL ,and other technologies and the latest IP/MPLS equipmentrom Alcatel-Lucent and other vendors. The center has been able to reduce migration schedules by50%, and its operational knowledge base is the broadest in the industry because o its global ocuson multivendor data network migration. With this centralized team o resources, it also ensures thesolution is implemented in the same manner in all migrations throughout the service provider network.
FR
Strategic approachfor migrations
Upfront migration planningsaved mid-sized European SP
25 million OPEX in 5 years
ATM
MOC
GNEICs
DSL
PL
Other
IP
MPLS
GMPLS
Ethernet
1
Migration Operation Centre (MOC)4
Intelligentcapability design
Get started in monthsrather than years
Experience with over 500 NEs
Major data and voice migrationsin 100+ countries and 70+ IP transformations
Reduces migration scheduleand execution resources
requirements by 50%
Set up and manage aMigration Operations 24x7
Coordination with NOC
Specializedlabs
100s of IPengineers
2 Fast and reliableexecutions
3
ALU
SRCs
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7. Conclusion
The Alcatel-Lucent 7705 SAR and 7750 SR provide a unique and powerul combination to helpyou transorm your legacy inrastructure and eectively take on business opportunities and deliveryrequirements pertaining to multimedia content, applications and Web 2.0 subscriber trac. Alcatel-Lucent possesses an unmatched experience in IP network transormation, with deployments in over60 carrier deployments worldwide. Our market-leading technology and expertise is at your service
and on display in one o our IP transormation centers near you.
8. References and sources
ApplyingtheAlcatel-Lucent7750ServiceRouterforMultiserviceBroadbandNetworkGateway.Application note
HighLeverageResidentialServiceDeliveryIPtransformationforprotablegrowth.Strategicwhite paper
IsocoreTechnicalReport.Alcatel-LucentResidentialServiceDeliverySolutionverication
Alcatel-Lucent7750ServiceRouter.Datasheet
9. Glossary of termsBNG broadband network gateway
BSAN broadband service access node
BRAS broadband remote access server
Capex captital expenditures
DHCP dynamic host confguration protocol
ESS Ethernet service switch
HSI high-speed Internet
IPTV Internet protocol television
MPLS Multiprotocol Label Switch
NPV Net Present Value
Opex Operational Expenditures
QoS quality o service
RADIUS remote authentication dial-in user service
RG residential gateway
SAR service aggregation router
SR service router
VLAN Virtual local area network
VLL Virtual leased Line Service
VPLS Virtual Private LAN Services
VoIP voice over IP
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www.alcatl-lct.c Alcatel, Lucent, Alcatel-Lucent and the Alcatel-Lucent logoare trademarks o Alcatel-Lucent. All other trademarks are the property o their respective owners.The inormation presented is subject to change without notice. Alcatel-Lucent assumes no responsibilityor inaccuracies contained herein. Copyright 2010 Alcatel-Lucent. All rights reserved.CPG2896101009 (11)