Fixed Mobile Convergence 2.0 Design Guide

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Fixed Mobile Convergence 2.0DESIGN GUIDE

September 2013


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Table of Contents

Table of Contents

Introduction .................................................................................................................................1

Executive Summary .................................................................................................................... 1

Release Notes............................................................................................................................. 7

Requirements ............................................................................................................................12

Service Provider Architectures ...................................................................................................12

Fixed and Mobile Converged Transport Characteristics ............................................................ 15

System Overview .......................................................................................................................20

System Concept ....................................................................................................................... 20

Transport Models ...................................................................................................................... 23

Flat LDP Core and Aggregation ............................................................................................ 25

Hierarchical-Labeled BGP LSP Core-Aggregation and Access ............................................ 25

Labeled BGP Redistribution into Access IGP ........................................................................ 26

Hierarchical-Labeled BGP LSP Core and Aggregation ......................................................... 27

Hierarchical-Labeled BGP LSP Core, Aggregation, and Access ........................................... 28

Hierarchical-Labeled BGP Redistribution into Access IGP .................................................... 29

Residential Wireline Service Models ......................................................................................... 29

Community Wi-Fi Service Models ............................................................................................ 34

Business Service Models .......................................................................................................... 36

Mobile Service Models ............................................................................................................. 40

System Architecture ..................................................................................................................43

Transport Architecture .............................................................................................................. 43

Large Network, Multi-Area IGP Design with IP/MPLS Access ............................................... 43

Large Network, Inter-AS Design with IP/MPLS Access ......................................................... 48

Large Network, Multi-Area IGP Design with non-IP/MPLS Access ....................................... 52

Large Network, Inter-AS Design with non-IP/MPLS Access ................................................. 54

Small Network, Integrated Core and Aggregation with IP/MPLS Access............................... 56

Small Network, Integrated Core and Aggregation with non-IP/MPLS Access ....................... 58

Residential Service Architecture ............................................................................................... 59Residential Wireline Service Architecture ............................................................................. 59

Community Wi-Fi Service Architecture ................................................................................ 71

Subscriber Experience Convergence ....................................................................................74


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Table of Contents

Business Service Architecture .................................................................................................. 82

MPLS VRF Service Model for L3VPN ................................................................................... 82

H-VPLS Service Model for L2VPN ....................................................................................... 85

PBB-EVPN Service Model for L2VPN ................................................................................... 86

PW Transport for X-Line Services ........................................................................................ 89

Mobile Service Architecture ...................................................................................................... 91

L3 MPLS VPN Service Model for LTE ................................................................................... 91Multicast Service Model for LTE eMBMS .............................................................................. 96

L2 MPLS VPN Service Model for 2G and 3G ....................................................................... 97

Inter-Domain Hierarchical LSPs ................................................................................................. 99

Inter-Domain LSPs for Multi-Area IGP Design ....................................................................... 99

Inter-Domain LSPs for Inter-AS Design ............................................................................... 103

Inter-Domain LSPs for Integrated Core and Aggregation Design ........................................ 108

Transport and Service Control Plane ........................................................................................ 110

BGP Control Plane for Multi-Area IGP Design ......................................................................110

BGP Control Plane for Inter-AS Design ................................................................................ 112

BGP Control Plane for Integrated Core and Aggregation Design ......................................... 115

Scale Considerations ............................................................................................................... 116

Functional Components ...........................................................................................................122

Quality of Service ....................................................................................................................122

Synchronization Distribution .....................................................................................................126

Redundancy and High Availability .............................................................................................129

Subscriber and Service Control and Support ...........................................................................132

Multicast ................................................................................................................................. 135Transport Integration with Microwave ACM ..............................................................................137

OAM and Performance Monitoring .......................................................................................... 139

Autonomic Networking ............................................................................................................ 143

Conclusion ..............................................................................................................................146

Related Documents .................................................................................................................149

Glossary ..................................................................................................................................150


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Introduction September 2013

1

Introduction

Executive Summary

Infused with intelligence and select solutions for scalability, agile transport, security, and more, the Cisco FixedMobile Convergence (FMC) system gives operators a proven architecture, platforms, and solutions to address

the dramatic changes in subscriber behavior and consumption of communications services, both fixed and

mobile access, and provide operational simplification, all at optimized cost points.

The Cisco FMC system defines a multi-year ongoing development program by Ciscos Systems Development

Unit (SDU) that builds towards a flexible, programmable, and cost-optimized network infrastructure, all targeted

to deliver in-demand fixed wireline and mobile network services. As the market leader in providing network

equipment in both fixed and mobile networks, Cisco is uniquely positioned to help providers transition network

operations, technologies, and services to meet these new demands. Cisco is delivering proven architectures

with detailed design and implementation guides as proof points of our strategy to service fixed and mobile

subscribers.

Through a sequence of graceful transitions, Cisco enables transition from legacy circuit-oriented architecturestowards powerful, efficient, flexible, and intelligent packet-based transport with the following proof points:

2012: Unified MPLS for Mobile Transport (UMMT) defines a Unified Multiprotocol Label Switching (MPLS)

Transport solution for any mobile backhaul service at any scale.

2013: Cisco FMC builds the network and service infrastructure convergence.

2014: Cisco FMC enables the unif ied and seamless fixed and mobile subscriber experience and its

extension to Bring Your Own Device (BYOD) access.

The key program benefits of the Cisco FMC system include:

Lowering the cost of operations compared to competing architectures and leveraging converged and

integrated transport.

Leveraging common service nodes (e.g., Carrier Grade NAT (CGNAT), Deep Packet Inspection (DPI),

etc.) across all classes of subscribers, regardless of access type.

Creating a unique user identity within the network that enables personalized and customized application

of policies to enabled services, including personalized access controls and personalized firewalls.

Delivering a clear system progression toward enabling per-subscriber cloud-based services accessed

from any device.

Creating more flexible business models by enabling capabilities like optimized business services over

long-term evolution (LTE) access.

Opening the network to programmable control via robust APIs.

The Cisco FMC system defines MPLS-based transport services and couples that transport closely to theservice delivery architecture. The MPLS transport aspects of the system validation are also directly applicable to

providers offering Layer 2 (L2) and Layer 3 (L3) transport as a service. To expand the transport protocol offerings

beyond MPLS, a separate carrier Ethernet transport system is being planned that will provide validated options

for native Ethernet (G.8032 control plane), network virtualization with satellites, and MPLS-TP.


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Challenge

The pace of change faced by operators in highly competitive markets continues to accelerate and using old

models of service specific networks or adding patches to networks based on legacy technologies no longer

makes economic sense. Whereas previously the most pressing questions for operators centered around meeting

point-to-point bandwidth demands, more complex questions now dominate discussions, such as the following:

How do I innovate services delivered by my network?

How do I lower cost in the face of exponential traffic growth?

How can I simplify operations while adding new services when my network has grown over a long period

of time to utilize multiple technologies and standards?

How can I personalize services in an automated fashion without arduous operational procedures?

How can I achieve the any service on any device at any location in a secure manner with consistent

quality of experience that my customers expect?

How can I monetize my network assets while enabling subscribers to use any device they want to

access services?

The context for these questions is one of dramatic growth and change. Whereas a fixed line operator traditionally

did not need to care about mobility, developments such as Wi-Fi, hotspots, and stadium technology are

broadening the definition of mobile solutions beyond traditional mobile handset voice and data. Likewise in theenterprise space, mobility of devices is a baseline requirement, with more and more users requiring secure

access to corporate data on their own tablet or other mobile device. This pervasive mobility across all services,

access types and end user devices pose challenges like the following:

How to apply appropriate access policies

How to keep data secure

How to build a comprehensive network access strategy

How to extend the right user experience to all these situations

Many of these challenges are being characterized into the BYOD definition. Initially, BYOD conversations in an

enterprise related to how the IT organization enabled an employee to use their own iPad at work. This created

challenges such as how to connect this device to the network, secure company data and applications, and dealwith lost or stolen devices. This initial conversation has expanded to include consideration for the following:

BYOD is about enabling:

Any person

Any device

Any ownership

Any access

This creates the following challenges for IT:

Pervasive, reliable mobility

Support many devices and operating systems

Many user types on the network

Easy on-boarding

Making applications portable

Extending the right experience


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Beyond these challenges that represent foundational issues related to BYOD, businesses like retailers and hotels

are recognizing the huge opportunity that customized services pushed to mobile devices held by their customers

represents in influencing and improving customer experience and thereby increasing revenues.

BYOD will transform how every business/entity provides IT to its employees, interacts with its customers, and

provides IT services. Challenges of this scale also represent opportunities for SPs to expand their list of offerings

and deliver new, innovative, and in-demand services to enhance revenue streams. The Cisco FMC system

addresses all challenges and positions the network as a platform to meet service and transport growth with

accompanying higher returns and operator profitability. The more functions that support this emerging BYODmovement that can be incorporated into the SP offerings, the more quickly businesses can adopt them and the

more quickly SPs can grow their revenue.

Solution

The Cisco FMC system provides reliable, scalable, and high-density packet processing that addresses mass

market adoption of a wide variety of fixed and mobile legacy services, while reducing the operators total cost

of operations (TCO) and the capability to deliver new, innovative, and in- demand services. It also handles

the complexities of multiple access technologies, including seamless handover and mobility between access

networks (2G, 3G, 4G LTE, and Wi-Fi) to meet demands for convergence, product consolidation, and a common

end-user service experience.

Figure 1 - Cisco Fixed Mobile Convergence System

2 9

3 2 0 0

Business Convergence: MPLS VPN services over Fixed and Mobile (LTE) Access

Residential Convergence: Common Service Experience Community Wi-Fi Service

Service Infrastructure Convergence

Fixed andWi-Fi Edge

ConvergedDPI

FixedCGN

FMCPCRF

MobileEPC Edge

Unified MPLS Transport

Transport Infrastructure Convergence

Subscriber Service Convergence

Enterprise Fixed

CorporateIP

Mobile Device

Residential Fixed

Wi-FiDevice

IP

Cisco FMC introduces key technologies from Ciscos Unified MPLS suite of technologies to deliver highly

scalable and simple-to-operate MPLS-based networks for the delivery of fixed wireline and mobile backhaul

services.


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For RAN backhaul of LTE services, operators are adopting MPLS over pure IP for two main reasons:

Investment in packet-based networks delivers an economic solution to the exponential growth in packet

traffic that needs transport. While the future lies with LTE, the present only offers 2G and 3G cell site

connectivity. Support for ATM and TDM traffic inherent in legacy networks must exist in order to move

traffic to the new higher-capacity LTE networks. The Multiprotocol Label Switching (MPLS) pseudowire is

the industry choice for achieving this over a packet infrastructure.

L3 MPLS VPNs in the RAN backhaul, which facilitate virtualization of the transport infrastructure, are

becoming common in LTE designs. This is useful when offering wholesale transport. It also leverages theRAN backhaul network for transport to other services for business and residential consumers.

Unified MPLS resolves legacy challenges such as scaling MPLS to support tens of thousands of end nodes,

which provides the required MPLS functionality on cost-effective platforms and the complexity of technologies

like Traffic Engineering Fast Reroute (TE-FRR) to meet transport SLAs.

By addressing the scale, operational simplification, and cost of the MPLS platform, Cisco FMC resolves the

immediate need to deploy an architecture that is suitable for a converged deployment and supports fixed

residential and business wireline services as well as legacy and future mobile service backhaul.

Figure 2 - Cisco FMC System Components



Service Infrastructure Convergence

Fixed andWi-Fi Edge

ConvergedDPI

FixedCGN

FMC

PCRFMobile

EPC Edge

Unified MPLS Transport

Transport Infrastructure Convergence


Enterprise Fixed

CorporateIP

Mobile Device

Residential Fixed

Wi-FiDevice

IP



Ser ce

Fixed anWi-Fi

onvergedDPI

FixedCGN

FMC

PCRFbile

Unifi nsport

Transport Inf Convergence


Enterprise Fixed

Corp

Residential Fixed

Wi-FiDevice

d r

a re

vice ergen

rate

Mob vic

IP

DHCPCisco PNR

CSGASR 901

CNCRS-3

PANASR-903

Open RG andIOS CPEs

Open RG andIOS CPEs

PANASR-9001

AGN-SEPAN-SEASR-900X

AGN-SEPAN-SEASR-900X

Virtualized Route Reflector

FANFTTB ME 3600XFTTH ME 2600X

FAN (PON,DSL, Ethernet)

ME 4600, 2600X

FAN (PON,DSL, Ethernet)ME 4600, 2600X

AAA, PCRFBroadhop QPS

2 9 3 2 0 1


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FMC Highlights

Decoupling of transport and service layers. Enables end-to-end MPLS transport for any service, at

any scale. Optimal service delivery to any location in the network is unrestricted by physical topological

boundaries.

Scaling of the MPLS infrastructure using RFC 3107 hierarchical LSPs. RFC 3107 procedures define the

use of Border Gateway Protocol (BGP) to distribute labels so that BGP can split up large routing domains

to manageable sizes, yet still retain end-to-end connectivity.

Optimal integration of wireline SE aspects in transport network . Residential Broadband NetworkGateway (BNG) and business Multiservice Edge (MSE) functions are integrated into the nodes

comprising the transport network, allowing for optimal distribution of the service edge and subscriber

SLA and policy enforcement in the network.

Common service experience. Enabled by a common Policy and Charging Rules Function (PCRF)

for both fixed and mobile networks, the customer service experience is for consumers and business

subscribers over fixed and mobile access with mediated subscriber identities and common services

transport and policies.

MPLS VPN over fixed and mobile access.Provides expanded addressable market to the service

provider for business service delivery to locations without fixed wireline access via 3G- or LTE-attached

services.

Service provider-managed public Wi-Fi services in the residential home. Provides the service

provider with expanded Wi-Fi service coverage through deployment via residential service connections.

Improved high availability. Multi-Router Automatic Protection Switching (MR-APS), pseudowire

redundancy, remote Loop-Free Alternate (LFA) to support arbitrary topologies in access and aggregation

to delivery zero configuration 50msec convergence, and labeled BGP Prefix-Independent Convergence

(PIC) for edge and core.

Simplified provisioning of mobile and wireline services. New service activation requires only endpoint

configuration.

Virtualization of network elements.Implementation of virtualized route reflector functionality on a Cisco

Unified Computing System (UCS) platform provides scalable control plane functionality without requiring

a dedicated router platform.

Highly-scaled MPLS VPNs support transport virtualization. This enables a single fiber infrastructure

to be re-utilized to deliver transport to multiple entities, including mobile for retail and wholesale

applications, residential, and business services. This enables the one physical infrastructure to support

multiple VPNs for LTE and wireline services.

Comprehensive Multicast support.Efficient and highly-scalable multicast support for residential,

business, and mobile services.

TDM circuit support. Addition of time-division multiplexing (TDM) circuit transport over packet for legacy

business TDM services and the Global System for Mobile Communications (GSM) Abis interface.

ATM circuit support.Addition of ATM transport over packet for legacy business ATM services and 3G

Iub support. Microwave support. Full validation and deployment recommendations for Ciscos microwave partners:

NEC (with their iPASOLINK product), SIAE (with their ALCPlus2e and ALFOplus products), and Nokia

Siemens Networks (NSN) (with their FlexiPacket offering).


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Synchronization distribution.A comprehensive synchronization scheme is supported for both frequent

and phase synchronization. Synchronous Ethernet is used in the core, aggregation, and access domains

where possible. Where SyncE may not be possible, based on the transmission medium, a hybrid

mechanism is deployed converting SynchE to IEEE 1588v2 timing. IEEE 1588v2 boundary clock function

in the aggregation to provide greater scalability. Cisco FMC now supports Hybrid SyncE and Precision

Time Protocol (PTP) with 1588 BC across all network layers.

QoS. Cisco FMC leverages Differentiated Services (DiffServ) quality of service (QoS) for core and

aggregation, H-QoS for microwave access and customer-facing service-level agreements (SLAs),

and support for LTE QoS class identif ier (QCIs) and wireline services, to deliver a comprehensive QoS

design.

OAM and Performance Monitoring. Operations, administration, and maintenance (OAM) and

performance management (PM) for Label-Switched Path (LSP) Transport, MPLS VPN, and Virtual Private

Wire Service (VPWS) services are based on IP SLA, pseudowire (PW) OAM, MPLS and MPLS OAM, and

future IETF MPLS PM enhancements.

LFA for Fast Reroute (FRR) capabilities.The required 50ms convergence time inherent in Synchronous

Optical Networking/Synchronous Digital Hierarchy (SONET/SDH) operations used to be achieved in

packet networks with MPLS TE-FRR. This has been successfully deployed in core networks, but not in

access networks due to the complexity of additional required protocols and overall design. LFA delivers

the same fast convergence for link or node failures without any new protocols or explicit configuration on

a network device. Hub-and-spoke topologies are currently supported, with a later release extending LFA

coverage to arbitrary topologies.

Until now, fixed network infrastructures have been limited to wireline service delivery and mobile network

infrastructures have been composed of a mixture of many legacy technologies that have reached the end of

their useful life. The Cisco FMC system architecture provides the first integrated, tested, and validated converged

network architecture, meeting all the demands of wireline service delivery and mobile service backhaul.

Cisco FMC Benefits

Flexible deployment options for multiple platformsto optimally meet size and throughput requirements

of differing networks.

High-performance solution,utilizing the highest capacity Ethernet aggregation routers in the industry.The components of this system can be in service for decades to come.

Tested and validated reference architecturethat allows operators to leverage a pre-packaged

framework for different traffic profiles and subscriber services.

Promotes significant capital savingsfrom various unique features such as pre-tested solutions,

benchmarked performance levels, and robust interoperability, all of which are validated and pre-

packaged for immediate deployment.

Enables accelerated time-to-market based on a pre-validated, turnkey system for wireline service

delivery and mobile service backhaul.

Complementary system support, with mobile video transport optimization integration; I- WLAN

untrusted offload support on the same architecture; Mobile Packet Core (MPC); and cost-optimizedperformance for Voice over LTE (VoLTE), plus additional services such as Rich Communication Suite

(RCS).

Ciscos IP expertise is available to operators deploying Cisco FMC through Cisco Services. These

solutions include physical tools, applications, and resources plus training and annual assessments

designed to suggest improvements to the operators network.


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Release NotesThese release notes outline the hardware and software versions validated as part of the Cisco FMC system

effort, the UMMT System efforts from before, and the key advancements of each system release.

Cisco FMC 2.0

Release 2.0 of the Cisco FMC system architecture further builds upon the architecture defined in the first release

with the addition of the following improvements:

Transport and Fixed Service Edge (FSE) convergence:

Remote LFA FRR and BGP PIC enhancements

Virtualized Route Reflector on Cisco Unified Computing System (UCS) platform

Unified MPLS transport for legacy access nodes

Residential Services:

Single stack IPv6 PPPoE and IPoE, N:1 and 1:1 residential access

MPLS transport for DSL access

Dual stack triple play services (IPv4 and IPv6 coexistence within the household)

Carrier Grade NAT MAP-T functions for IPv4 services, co-located with residential BNG SE

Overlay of community Wi-Fi access over traditional wireline access transport

Unified Subscriber Experience use cases for residential wireline, community Wi-Fi and mobile

access

PCRF provided by Cisco Quantum Policy Suite

Business Services:

L2VPN services via Ethernet VPN (EVPN) with Provider Backbone Bridge (PBB)

MPLS L3VPN Business Services over Fixed and Mobile (3G and LTE) Access

Mobile Services:

Enhanced Multimedia Broadcast Multicast Service (eMBMS) support

Enhancements to Hybrid Synchronization distribution model


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Table 1 - Cisco FMC 2.0 Platforms and Software Versions

Architectural Role Hardware Software Revision

Core node ASR 9000

CRS-3

XR 4.3.1

XR 4.3.1

Aggregation node + service edge ASR 9006 XR 4.3.2

Pre-aggregation node + service edge ASR 9001 XR 4.3.2

Pre-aggregation node ASR 903

ME3600X-24CX

XE 3.10

XE 3.10

Fixed access node ME3600X-24CX XE 3.10

Gigabit passive optical network (GPON) optical link terminator (OLT) ME4600 3.1.0

Cell Site Gateway (CSG) ASR 901 XE 3.11

Mobile Transport Gateway (MTG) ASR 9000 XR 4.3.1

Virtualized route reflector IOS-XR Virtual Router XR 4.3.2

DHCP Prime Network Registrar 8.1

PCRF QPS PCRF 5.3.5

Service management QPS Portal/PCRF/SPR 5.3.5Subscriber management QPS SPR/AAA 5.3.5

Cisco FMC 1.0

Release 1.0 of the Cisco FMC system architecture expands upon the Unified MPLS models first developed in the

UMMT System to include residential and business wireline service delivery alongside mobile service backhaul.

Some of the key areas of coverage are listed here:

Transport and fixed service edge convergence:

Unified MPLS Transport with MPLS access for mobile and business and Ethernet access for residential

Fixed edge convergence and optimal placement: dual stack fixed edge and policy integration for

residential services

Residential Services:

Dual stack PPPoE and IPoE, N:1 and 1:1 residential triple play services

EVC edge for access and service edge

Carrier Grade NAT co-location with residential BNG SE

PCRF provided by Bridgewater Services

Business Services:

Dual stack MPLS VPN, VPWS, and VPLS services.

Converged fixed edge with optimal placement and integration of the business edge.

Pseudowire headend (PWHE) provides direct MPLS-based transport of services to the businessservice edge node.

Mobile Services:

Maintain mobile backhaul established in UMMT.

Microwave ACM integration with IP/MPLS transport.

Microwave partnerships with SIAE, NEC, and NSN.

Comprehensive NMS with Cisco Prime.


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Table 2 - Cisco FMC 1.0 Platforms and Software Versions


Core node ASR 9000

CRS-3

XR 4.3.1

XR 4.3.1

Aggregation node + service edge ASR 9006 XR 4.3.1

Pre-aggregation node + service edge ASR 9001 XR 4.3.1


ME3600X-24CX

XE 3.9

XE 3.9

Fixed access node ME3600X-24CX XE 3.9

Cell Site Gateway (CSG) ASR 901 Release 2.2


Network management Prime Management Suite 1.1

UMMT 3.0

Release 3.0 of the Cisco UMMT system architecture further builds upon the architecture defined in the first two

releases with the addition of the following improvements: New Unified MPLS models:

Labeled BGP access, which provides highest scalability plus wireline coexistence

v6VPN for LTE transport

IEEE 1588v2 Boundary clock (BC) and SyncE/1588v2 Hybrid models:

Greater scalability and resiliency for packet-based timing in access and aggregation

ATM/TDM transport end-to-end:

ATM provides transport for legacy 3G services

PW redundancy with Multirouter Automatic Protection Switching (MR-APS)

New network availability models:

Remote LFA FRR

Labeled BGP PIC core and edge

BGP PIC edge for MPLS VPN

Most comprehensive resiliency functionality

ME3600X-24CX platform:

2RU fixed-configuration 40Gb/s platform

Supports Ethernet and TDM interfaces

Network management, service management, and assurance with Prime


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Table 3 - Cisco UMMT 3.0 Platforms and Software Versions


Core node ASR 9000

CRS-3

XR 4.2.1 / 4.3.0

XR 4.2.1

Aggregation node ASR 9000 XR 4.2.1 / 4.3.0


ME 3600X-24CX

XE 3.7 / 3.8

15.2(2)S1

Cell Site Gateway (CSG) ASR 901 15.2(2)SNG

Mobile Transport Gateway (MTG) ASR 9000 XR 4.2.1 / 4.3.0

Network management Prime Management Suite 1.1

Cisco UMMT 2.0

Release 2.0 of the Cisco UMMT system architecture continues to build upon the baseline established by release

1.0 by implementing the following improvements:

Introduction of ASR 903 modular platform as a pre-aggregation node (PAN).

Any Transport over MPLS (AToM): Complete TDM transport capabilities in access and aggregationdomains with Circuit Emulation over Packet Switching Network (CESoPSN) and Structure Agnostic

Transport over Packet (SAToP) TDM Circuit Emulation over Packet (CEoP) services on the ASR 903 and

ASR 9000 platforms.

200Gbps/Slot line cards and new supervisor cards for the ASR 9000, which bring increased scalability,

100G Ethernet support, and synchronization enhancements with 1588 BC support.

BGP PIC edge and core on ASR 9000 for labeled Unicast.

Microwave partnerships with NEC and NSN.



Core node ASR 9000

CRS-3

XR 4.2

XR 4.2

Aggregation node ASR 9000 XR 4.2


ME3800X

XE 3.5.1.S

15.1(2.0.47)EY0

Cell Site Gateway (CSG) ASR 901 15.1(2)SNH

Mobile Transport Gateway (MTG) ASR 9000 XR 4.2

Packet microwave NSN FlexiPacket 2.4

Hybrid microwave NEC iPASOLINK 2.02.29


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The first release of the Cisco UMMT System architecture formed the baseline for a highly scalable and

operationally-simplified system architecture to deliver mobile backhaul services:

Introduction of RFC3107-compliant-labeled BGP control plane in the access, aggregation, and core

network domains

Introduction of hierarchical LSP functionality to provide abstraction between transport and service layers

MPLS L3VPN-based backhaul of S1 and X2 interfaces for LTE deployment.

Simplified provisioning of mobile backhaul services enabled by BGP-based control plane. Only endpointconfiguration needed for service enablement

LFA functionality provides FRR capabilities in a greatly operationally-simplified manner

End-to-end OAM and PM functionality for mobile backhaul services and transport layer



Core node ASR 9000

CRS

IOS-XR 4.1.1

IOS-XR 4.1.1

Aggregation node ASR 9000 IOS-XR 4.1.1

Pre-aggregation node ME3800X IOS 15.1(2)EY1

Cell Site Gateway (CSG) MWR2941

ASR 901

IOS 15.1(1)MR

IOS 15.1(2)SNG



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Requirements September 2013

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Requirements

Service Provider Architectures

Over the past two decades with the pace of change constantly accelerating, service providers (SPs) haveoffered dramatically altered services. Fifteen years (or more) ago, the SP was mainly concerned with offering

point-to-point transport. Now, dozens of VPN offerings to enterprises, along with rich residential offerings, create

hundreds of options for different services to be carried on SP networks. This explosion of service offerings has

typically not been matched with an equivalent restructuring of the SP network. The most common practice has

been to add additional stove-piped networks or new protocols that enable offering new services. While each

decision to patch the existing infrastructure has made sense, in many situations the collection of decisions has

created a complex, unwieldy, and difficult to manage network while provisioning new services is time consuming

It is apparent that the network environment of the last decade doesnt reflect the conditions SPs face today.

Older networks were created based on the following environmental conditions:

Initially sparse customer-take rates for broadband

Business services dominating the bandwidth

Relatively low data bandwidth usage per user

Reuse of Synchronous Digital Hierarchy (SDH) and Synchronous Optical Networking (SONET) TDM

transport infrastructure.

Internet access self-tuning aggregation traffic dominance

Conservative growth assumptions

Low availability of IP operations expertise


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Looking at todays environment, none of those conditions apply. In addition to environmental factors, there are

more demands placed on SP networks, and these networks are in the midst of dramatic change. Consider the

following figure.

Figure 3 - Revenue Split and Traffic Predictions

100%

90%80%

70%

60%

50%

40%

30%

20%

10%

0%

293329

Legacy Layer 2

% Total Revenue 2011

Approx. 2008 Est. 2015

Packet

Layer 1 and Layer 2

Fixed and Mobile Voice

Layer 3 Transport and Services

Packet

Circuit

Private Line

TDM/OTNTraffic

~50-70%*

Private/PublicIP Traffic

~30-50%

2013

Private Line

TDM/OTNTraffic

20-30%


70-80%

2016

90+%IP Traffic

LegacyTDM

Traffic

Private Line

TDM/OTNTraffic

0-10%


90+%

SP revenue is shifting from circuits to packet services (Cisco Research 2010), with approximately 80% of

revenue to be derived from packet services in five years

Packet traffic is increasing at 23% compound annual growth rate (CAGR) (Cisco VNI 2013)

SP traffic make-up is expecting a massive change in next f ive years (ACG Research 2011)

The economic realities depicted in Figure 4show how this shift towards packet-based services and traffic drives

a preference for packet-based transport. Essentially, the statistical multiplexing benefits of packet transport for

packet traffic outweigh other considerations compared to using legacy TDM transport for packet transport oneconomic grounds.

This point is illustrated in Figure 4. The figure takes an example of how to provision bandwidth for ten 1-Gigabit

per second flows. If bandwidth is provisioned for each flow by using TDM technology, a gigabit of bandwidth is

permanently allocated for each flow because there is no way to share unused bandwidth between containers

in a TDM hierarchy. Contrast that to provisioning those flows on a transport that can share unused bandwidth

via statistical multiplexing, and it is possible to provision much less bandwidth on a core link. For networks that

transport primarily bursty data traffic, this is now the norm, rather than the exception.


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Figure 4 - Economic Realities

293330

10 1GE Flows Actual Traffic Traffic Aggregatedon a Packet Network

Traffic Aggregatedon a Circuit Network

Provisioning:Sum of Peak

Flows

Provisioning for Circuit/OTN and Packet/Router Aggregation

Chart from Infonetics, text from DT

Provisioning:Sum of AverageFlows + a Few

Peak Flows

This analysis indicates the following:

TDM transport of packets is no longer economically viable and lacks statistical multiplexing, which makes

it very expensive.

Full transformation to Next Generation Networks (NGN) needs to occur from core to customer.

Long term vision is critical because this will be the network for the next decade.

Packet transport with MPLS to enable virtualization of the infrastructure and support for legacy protocols

via pseudowires is the most effective technology choice because it will:

Minimize capital expenditure (CAPEX) and operating expenses (OPEX).

Provide carrier class service delivery.

Maximize service agility.

Beyond simple efficiencies of transport, greater intelligence within the network is needed in order to cope

efficiently with the avalanche of data traffic. AT&T, for example, calculates caching at the edge of their network

can save 30% of core network traffic, which represents tens of millions of dollars of savings every year. With the

dynamic nature of traffic demands in todays network, IP and packet transport is adept at adjusting very quickly

to new traffic flow demands via dynamic routing protocols. TDM and Layer 2 approaches, however, are slow to

adapt because paths must be manually reprovisioned in order to accommodate new demands.

Future Directions

Starting today, there is convergence of transport across all services, leading towards convergence of edge

functions and ultimately a seamless and unified user experience enabling any service on any screen in

any location. This will be accomplished over a network with standardized interfaces enabling fine-grained

programmatic control of per-user services. Ciscos FMC program meets all of the demands and challenges

defined for cost-optimized packet transport, while offering sophisticated programmability and service

enablement.


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Fixed and Mobile Converged Transport CharacteristicsNetworks are an essential part of business, education, government, and home communications. Many residential

business, and mobile IP networking trends are being driven largely by a combination of video, social networking

and advanced collaboration applications, termed visual networking.

Annually, Cisco Systems publishes the Cisco Visual Networking Index (VNI), an ongoing initiative to track and

forecast the impact of visual networking applications. This section presents highlights from the 2012 to 2017

VNI and other sources give context to trends in the SP space that are driving increases in network capacity andconsolidation of services in a unified architecture.

Executive Overview

Annual global IP traffic will surpass the zettabyte threshold (1.4 zettabytes) by the end of 2017.In

2017, global IP traffic will reach 1.4 zettabytes per year or 120.6 exabytes per month.

Global IP traffic has increased more than fourfold over the past 5 years, and will increase threefold

over the next 5 years. Overall, IP traffic will grow at a Compound Annual Growth Rate (CAGR) of 23

percent from 2012 to 2017.

Metro traffic will surpass long-haul traffic in 2014, and will account for 58 percent of total IP traffic

by 2017. Metro traffic will grow nearly twice as fast as long-haul traff ic from 2012 to 2017. The higher

growth in metro networks is due in part to the increasingly significant role of content delivery networks,which bypass long-haul links and deliver traffic to metro and regional backbones.

Content Delivery Networks (CDNs) will carry over half of Internet traffic in 2017. Globally, 51 percent o

all Internet traffic will cross content delivery networks in 2017, up from 34 percent in 2012.

The number of devices connected to IP networks will be nearly three times as high as the global

population in 2017. There will be nearly three networked devices per capita in 2017, up from nearly two

networked devices per capita in 2012. Accelerated in part by the increase in devices and the capabilities

of those devices, IP traffic per capita will reach 16 gigabytes per capita in 2017, up from 6 gigabytes per

capita in 2012.

Traffic from wireless and mobile devices will exceed traffic from wired devices by 2016.By 2017,

wired devices will account for 45 percent of IP traffic, while Wi-Fi and mobile devices will account for 55

percent of IP traffic. In 2012, wired devices accounted for the majority of IP traffic at 59 percent.

Globally, consumer Internet video traffic will be 69 percent of all consumer Internet traffic in 2017,

up from 57 percent in 2012.Video exceeded half of global consumer Internet traffic by the end of 2011.

Note that this percentage does not include video exchanged through point-to-point (P2P) file sharing.

The sum of all forms of video (TV, video on demand (VoD), Internet, and P2P) will be in the range of 80

to 90 percent of global consumer traffic by 2017.

Internet video to TV doubled in 2012.Internet video to TV will continue to grow at a rapid pace,

increasing fivefold by 2017. Internet video to TV traffic will be 14 percent of consumer Internet video

traffic in 2017, up from 9 percent in 2012.

VoD traffic will nearly triple by 2017. The amount of VoD traff ic in 2017 will be equivalent to 6 billion

DVDs per month. Business IP traffic will grow at a CAGR of 21 percent from 2012 to 2017.Increased adoption of

advanced video communications in the enterprise segment will cause business IP traffic to grow by a

factor of 3 between 2012 and 2017.

Business Internet traffic will grow at a faster pace than IP WAN. IP WAN will grow at a CAGR of 13

percent, compared to a CAGR of 21 percent for fixed business Internet and 66 percent for mobile

business Internet.


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Business IP traffic will grow fastest in the Middle East and Africa. Business IP traffic in the Middle

East and Africa will grow at a CAGR of 29 percent, a faster pace than the global average of 21 percent.

In volume, Asia Pacific will have the largest amount of business IP traffic in 2017 at 8.3 exabytes per

month. North America will be the second at 5.4 exabytes per month.

Globally, mobile data traffic will increase 13-fold between 2012 and 2017. Mobile data traffic will grow

at a CAGR of 66 percent between 2012 and 2017, reaching 11.2 exabytes per month by 2017.

Global mobile data traffic will grow three times faster than fixed IP traffic from 2012 to 2017. Global

mobile data traffic was 2 percent of total IP traffic in 2012, and will be 9 percent of total IP traffic in 2017.

High Capacity Requirements from Edge to Core

The landscape is changing for consumer behavior in both wireline and mobile services. Increases in wireline

demands will come primarily from video applications. Powerful new mobile devices, increasing use of mobile

Internet access, and a growing range of data-hungry applications for music, video, gaming, and social networking

are driving huge increases in data traffic. As shown in the Cisco VNI projections, these exploding bandwidth

requirements are driving high capacity requirements from the edge to the core with typical rates of 100 Mbps

per eNodeB, 1Gbps access for mobile and wireline, 10-Gbps aggregation, and 100-Gbps core networks.

Figure 5 - Cisco VNI: Global IP Traffic, 2012 to 2017

293379

140

Exabytes per Month

Source: Cisco VNI, 2013

70

101 EB

121 EB

23% CAGR 2012-2017

69 EB

56 EB

44 EB

0

2012 2013 2014 2015 2016 2017

84 EB

Support for Multiple and Mixed Topologies

Many options exist for physical topologies in the SP transport network, with hub-and-spoke and ring being

the most prevalent. Capacity requirements driven by subscriber density, CAPEX of deploying fiber in large

geographies, and physical link redundancy considerations could lead to a combination of fiber and microwave

rings in access, fiber rings, and hub-and-spoke in aggregation and core networks. The transport technology

that implements these networks must be independent of the physical topology, or combination thereof, used

in various layers of the network, and must cost-effectively scale to accommodate the explosive increase in

bandwidth requirements imposed by growth in mobile and wireline services.


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Exponential Increase in Scale Driven by LTE Deployments

LTE will drive ubiquitous mobile broadband with its quantum leap in uplink and downlink transmission speeds.

In denser populations, the increased data rates delivered to each subscriber will force division of the cell

capacity among fewer users. Because of this, cells must be much smaller than they are today.

Another factor to consider is the macro cell capacity. The spectrum allotted to mobile networks has

been increasing over the years, roughly doubling over a five year period. With advancements in radio

technology, a corresponding increase in average macro cell efficiency has occurred over the same

period. As a result, the macro cell capacity, which is a product of these two entities, will see a four-fold

increase over a five year period. This increase, however, is nowhere close to the projected 26-fold

increase in mobile data (as stated above), and will force mobile operators to deploy a small-cell network

architecture.

These two factors will force operators to adopt small cell architectures, resulting in an exponential increase in cel

sites deployed in the network. In large networks covering large geographies, the scale is expected to be in the

order of several tens of thousands to a few hundred thousands of LTE eNodeBs and associated CSGs.

Figure 6 - Macro Cell Capacity

293380

Growth

Source: Agilent

26x Growth

1000

10

100

1

1990 1995 2000 2005 2010 2015

Macro CapacityAverage MacroCell Efficiency

Spectrum

Seamless Interworking with the Mobile Packet Core

As mentioned in the previous section, the flattened all-IP LTE/EPC architecture is a significant departure from

previous generations of mobile standards and should be an important consideration in designing the RAN

backhaul for 4G mobile transport.

The 2G/3G hierarchical architecture consists of a logical hub-and-spoke connectivity between base station

controller/radio network controller (BSC/RNC) and the base transceiver station (BTS)/NodeBs. This hierarchicalarchitecture lent itself naturally to the circuit-switched paradigm of having point-to-point connectivity between

the cell sites and controllers. The reach of the RAN backhaul was also limited in that it extended from the radio

access network to the local aggregation/distribution location where the controllers were situated.


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In contrast, the flat LTE architecture does away with the hierarchy by getting rid of the intermediate controller

like the BSC/RNC and letting the eNodeB communicate directly with the EPC gateways. It also does away with

the point-to-point relationship of 2G, 3G architectures and imposes multipoint connectivity requirements at the

cell site. This multipoint transport requirement from the cell site not only applies to the LTE X2 interface, which

introduces direct communication between eNodeBs requiring any-to-any mesh network connectivity, but also

to the LTE S1 interface, which requires a one-to-many relationship between the eNodeB and multiple Evolved

Packet Core (EPC) gateways.

While the Security Gateway (SGW) nodes may be deployed in a distributed manner closer to the aggregationnetwork, the Mobility Management Entities (MME) are usually fewer in number and centrally located in the

core. This extends the reach of the Radio Access Network (RAN) backhaul from the cell site deep into the core

network.

Important consideration also needs to be given to System Architecture Evolution (SAE) concepts like MME

pooling and SGW pooling in the EPC that allow for geographic redundancy and load sharing. The RAN backhaul

service model must provide for eNodeB association to multiple gateways in the pool and migration of eNodeB

across pools without having to re-architect the underlying transport architecture.

Figure 7 - RAN Backhaul Architecture

293381

LTE/EPC Flattened Backhaul Architecture

2G/3G Hierarchical Backhaul Architecture

eNode B

eNode B

SGW/PGW

PGW

S1-C

S1-C

SGW

MME

MME

X2

S1-U

S1-U

BTS/Node B

BTS/Node B

SGSN

MSC

GGSN

RAN Aggregation Core

Abis/lub

BSC/RNC


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System Overview September 2013

20

System Overview

System Concept

The Cisco Fixed Mobile Convergence (FMC) system defines a multi-year ongoing development effort, buildinga flexible, programmable and cost-optimized network infrastructure targeted to deliver in-demand fixed wireline

and mobile network services. FMC provides the architectural baseline for creating a scalable, resilient, and

manageable network infrastructure that optimally integrates the fixed wireline service edge and interworks with

the Mobile Packet Core (MPC).

The system is designed to concurrently support residential triple play, business L2VPN and L3VPN, and multiple

generation mobile services on a single converged network infrastructure. In addition, it supports:

Graceful introduction of long-term evolution (LTE) with existing 2G/3G services with support for

pseudowire emulation (PWE) for 2G GSM and 3G UMTS/ATM transport.

L2VPNs for 3G UMTS/IP, and L3VPNs for 3G UMTS/IP and 4G LTE transport.

Broadband Network Gateway (BNG) co-located with Carrier-Grade NAT for residential services. Multiservice Edge (MSE) pseudowire headend (PWHE) termination for business services.

Multicast transport.

Network synchronization (physical layer and packet based).

Hierarchical-QoS (H-QoS).

Operations, administrations, and maintenance (OAM).

Performance management (PM).

Fast convergence.

The Cisco FMC system meets the Broadband Forum TR-101 requirements for residential services and supports

all MEF requirements for business services. The FMC system also meets all Next-Generation Mobile Network

(NGMN) requirements for next-generation mobile backhaul, and innovates on the Broadband Forum TR-221

specification for MPLS in mobile backhaul networks by unifying the MPLS transport across the access,

aggregation, and core domains.

Simplification of the End-to-End Mobile Transport and Service Architecture

A founding principle of the Cisco FMC system is the simplification of the transport architecture by eliminating the

control and management plane translations that are inherent in legacy designs. As described in Service Provider

Architectures, traditional backhaul architectures relying on L2 transport are not optimized for converged service

delivery, nor for a flat all-IP architecture to support LTE transport. Furthermore, backhaul architectures built over

mixed L2 and L3 transport are inherently complex to operate. The FMC System enables a Unified L3 MPLS/IP

Transport extending end-to-end across the system.

It simplifies the control plane by providing seamless MPLS Label-Switch Paths (LSP) across access, pre-

aggregation, aggregation/distribution, and core domains of the network. In doing so, a fundamental attribute

of decoupling the transport and service layers of the network and eliminating intermediate touchpoints in the

backhaul is achieved. By eliminating intermediate touchpoints, it simplifies the operation and management of the

service. Service provisioning is restricted only at the edges of the network where it is required. Simple carrier

class operations with end-to-end OAM and performance monitoring services are made possible.


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Convergence

A key aspect of the Cisco FMC System is service convergence, enabling the ability to provide any service to any

part of the network. Some examples of service convergence provided by the Cisco FMC solution are:

Convergence of fixed residential and business service edges in a single node.

Optimal placement of fixed-access residential service edge role in the Unified MPLS Transport.

Optimal integration and placement of Fixed-access business service edge role in the Unified MPLS

Transport. Integration of CGN address translation for fixed access residential services with other residential service

edge functions.

Integration of fixed and mobile transport services in the Unified MPLS Transport, including support of all

services on a single Access Node (AN).

Optimal Integration of Wireline Service Edge Nodes

The Cisco FMC system integrates service edge aspects directly with the transport functions of the network

design. Such integration allows for optimal placement of edge functions within the network in order to address

a particular type of service. Service nodes providing residential BNG and CGN functions can be co-located

in the central office (CO) with the Access Nodes: Passive Optical Networks (PON) optical line terminal (OLT)

equipment, Fiber to the Home (FTTH) access nodes, etc. Business MSE functions can be located optimally inthe network, either in an aggregation node (AGN) or Pre-Aggregation Node (PAN), depending upon operator

preference and scalability needs.

Access nodes (AN) transport multipoint business services to these service edge nodes via Ethernet over MPLS

(EoMPLS) pseudowires, and connect to the proper service transport: Virtual Private LAN services (VPLS) virtual

forwarding instance (VFI) for E-LAN and MPLS VPN for L3VPN. PW to L3VPN interworking on the service edge

node is accomplished via PWHE functionality. VPWS services, such as E-Line and Circuit Emulation over Packet

(CEoPs), are transported directly between ANs via pseudowires.

Flexible Placement of L3 and L2 Transport Virtualization Functions for Mobile Backhaul

The hierarchical RAN backhaul architecture of 2G and 3G releases involved an intermediate agent like the BSC/

RNC, which mostly resided at the aggregation/distribution layer of the transport network.


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This simplified the requirements on the transport in that it only required connectivity between the RAN access

and aggregation network layers. In comparison, 4G LTE imposes many new requirements on the backhaul:

Because of the any-to-any relationship between eNodeBs for the X2 interface and the one-to-many

relationship between eNodeBs and EPC gateways (SGWs, MMEs) for the S1-u/c interface, the eNodeBs

and associated CSGs in the RAN access need both local connectivity and direct connectivity to the EPC

gateways in the MPC.

The stringent latency requirements of the X2 interface requires a logical mesh connectivity between

CSGs that introduces the minimum amount of delay that is in the order of 30ms. The minimum delayis expected to reduce further to around 10ms for features such as collaborative multiple input multiple

output (MIMO) in the future with 3GPP LTE Release 10 and beyond.

The Evolved Universal Terrestrial Radio Access Network (E-UTRAN)/EPC architecture supports MME

pooling and SGW pooling to enable geographic redundancy, capacity increase, load sharing, and

signaling optimization. This requires the transport infrastructure to provide connectivity from eNodeBs in

the RAN access to multiple MME and SGWs within these pools in the core network.

The introduction of LTE into an existing 2G/3G network has to be graceful and the transition will take

time. During this period, it is natural for a few centralized EPC gateways to be initially deployed and

shared across different regions of the network. As capacity demands and subscriber densities increase,

it is expected that new gateways will be added closer to the regions and subscribers will have to be

migrated. While the migration across gateways within the packet core could be done seamlessly basedon gateway pooling, it is imperative that the underlying transport infrastructure requires minimal to no

provisioning changes to allow the migration.

In 2G and 3G releases, the hub-and-spoke connectivity requirement between the BSC/RNC and the BTS/NodeB

makes L2 transport using Ethernet bridging with VLANs or P2P PWs with MPLS PWE3 appealing. In contrast, a

L3 transport option is much better suited to meet the myriad of connectivity requirements of 4G LTE. The UMMT

architecture provides both L2 and L3 MPLS VPN transport options that provide the necessary virtualization

functions to support the coexistence of LTE S1-u/c, X2, interfaces with GSM Abis TDM and UMTS IuB ATM

backhaul. The decoupling of the transport and service layers of the network infrastructure and the seamless

connectivity across network domains makes the system a natural fit for the flat all-IP LTE architecture by allowing

for the flexible placement of 2G/3G/4G gateways in any location of the network to meet all the advance backhaul

requirements listed above.

Deliver New Levels of Scale for MPLS Transport with RFC-3107 Hierarchical-Labeled BGP LSPs

As described in Fixed and Mobile Converged Transport Characteristics, supporting the convergence of fixed

wireline and mobile services will introduce unprecedented levels of scale in terms of number of ANs and services

connected to those nodes. While L2 and L3 MPLS VPNs are well suited to provide the required virtualization

functions for service transport, inter-domain connectivity requirements for business and mobile services present

challenges of scale to the transport infrastructure. This is because IP aggregation with route summarization

usually performed between access, aggregation, and core regions of the network does not work for MPLS,

as MPLS is not capable of aggregating Forwarding Equivalence Class (FEC). RFC-5283provides a kind of

mechanism for aggregating FEC via longest match mechanism in LDP, but it is not widely deployed and requires

significant reallocation of IP addressing in existing deployments to implement. In normal MPLS deployments, the

FEC is typically the PEs /32 loopback IP address. Exposing the loopback addresses of all the nodes (10k -100k)across the network introduces two main challenges:

Large flat routing domains adversely affect the stability and convergence time of the Interior Gateway

Protocol (IGP).

The sheer size of the routing and MPLS label information control plane and forwarding plane state

will easily overwhelm the technical scaling limits on the smaller nodes (ANs and PANs) involved in the

network.
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Unified MPLS elegantly solves this problem with a divide-and-conquer strategy of isolating the access,

aggregation, and core network layers into independent and isolated IGP domains. Label Distribution Protocol

(LDP) is used for setting up LSPs within these domains, and RFC-3107BGP-labeled unicast is used for setting

up LSPs across domains. This BGP-based inter-domain hierarchical LSP approach helps scale the network to

hundreds of thousands of AN sites without overwhelming any of the smaller nodes in the network, and does not

require any address reallocation as RFC 5283. At the same time, the stability and fast convergence of the small

isolated IGP domains corresponding to various network layers are maintained.

Transport ModelsThe Cisco FMC System incorporates a network architecture designed to consolidate transport of fixed wireline

and mobile services in a single network. Continued growth in residential and business services, combined with

ubiquitous mobile broadband adoption driven by LTE, will introduce unprecedented levels of scale in terms of

eNodeBs and ANs into the FMC network. This factor, combined with services requiring connectivity from the

access domain all the way to and across the core network, introduces challenges in scaling the MPLS network.

As previously mentioned, the endpoint identif ier in MPLS is the PEs /32 loopback IP address, so IP aggregation

with route summarization cannot be performed between the access, aggregation, and core regions of the

network. All network technologies meet a scale challenge at some point and the solution is always some form of

hierarchy to scale. The Unified MPLS Transport basis of the FMC System is no different, and uses a hierarchical

approach to solve the scaling problem in MPLS-based end-to-end deployments.Unified MPLS adopts a divide-and-conquer strategy where the core, aggregation, and access networks are

partitioned in different MPLS/IP domains. The network segmentation between the core and aggregation domains

could be based on a single autonomous system (AS) multi-area design, or utilize a multi-AS design with inter-AS

organization. Regardless of the type of segmentation, the Unified MPLS transport concept involves partitioning

the core, aggregation, and access layers of the network into isolated IGP and LDP domains. Partitioning these

network layers into such independent and isolated IGP domains helps reduce the size of routing and forwarding

tables on individual routers in these domains, which leads to better stability and faster convergence. LDP is used

for label distribution to build LSPs within each independent IGP domain. This enables a device inside an access,

aggregation, or core domain to have reachability via intra-domain LDP LSPs to any other device in the same

domain. Reachability across domains is achieved using RFC 3107 procedures whereby BGP-labeled unicast is

used as an inter-domain LDP to build hierarchical LSPs across domains. This allows the link state database of the

IGP in each isolated domain to remain as small as possible, while all external reachability information is carried via

BGP, which is designed to scale to the order of millions of routes.

In Single AS Multi-Area designs, interior Border Gateway Protocol (iBGP)-labeled unicast is used to build

inter-domain LSPs.

In Inter-AS designs, iBGP-labeled unicast is used to build inter-domain LSPs inside the AS, and exterior

Border Gateway Protocol (eBGP)-labeled unicast is used to extend the end-to-end LSP across the AS

boundary.

In both cases, the Unified MPLS Transport across domains will use hierarchical LSPs that rely on a BGP-

distributed label used to transit the isolated MPLS domains, and on a LDP-distributed label used within the AS to

reach the inter-domain area border router (ABR) or autonomous system boundary router (ASBR) corresponding

to the labeled BGP next hop.

The Cisco FMC system integrates key technologies from Ciscos Unified MPLS suite of technologies to deliver a

highly scalable and simple-to-operate MPLS-based converged transport and service delivery network. It enables

a comprehensive and flexible transport framework structured around the most common layers in SP networks:

the access network, the aggregation network, and the core network. The transport architecture structuring takes

into consideration the type of access and the size of the network.
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Access Type

MPLS Packet Access:

Covers point-to-point links, rings, and hierarchical topologies.

Applies to both fiber and newer Ethernet microwave-based access technologies with the MPLS

access network enabled by the ANs.

Services include both mobile and wireline services and can be enabled by the ANs in the access

network and the PANs or AGNs in the aggregation network.

IP/Ethernet/TDM Access:

Includes native IP or Ethernet links in point-to-point or ring topologies over fiber and newer

Ethernet microwave-based access.

Supports Central Office (CO) located PON OLT access.

Covers point-to-point TDM+Ethernet links over hybrid microwave access.

The MPLS services are enabled by the aggregation network and includes residential; business

X-Line, E-LAN, and L3VPN; Mobile GSM Abis, ATM IuB, IP IuB, and IP S1/X2 interfaces

aggregated in MPLS PANs or AGNs.

Network Size Small Network:

Applies to network infrastructures in small geographies where the core and aggregation network

layers are integrated in a single domain.

The Single IGP/LDP domain includes less than 1000 core and AGNs nodes.

Large Network:

Applies to network infrastructures built over large geographies.

The core and aggregation network layers have hierarchical physical topologies that enable IGP/

LDP segmentation.

This transport architecture structuring based on access type and network size leads to six architecture modelsthat fit various customer deployments and operator preferences as shown in the following table, and described in

the sections below.

Table 6 - FMC Transport Models

Access Type Small Network Large Network

Ethernet/TDM access Flat LDP core and aggregation network Hierarchical-labeled BGP core and aggregation network

MPLS access Hierarchical-labeled BGP LSP access network Hierarchical-labeled BGP LSP access network

MPLS access (mobile only) Labeled BGP redistribution into access IGP/LDP(optional LDP Downstream-on-Demand [DoD])

Hierarchical-labeled BGP redistribution into accessIGP/LDP (optional LDP DoD)


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Flat LDP Core and Aggregation

This architecture model applies to small geographies where core and aggregation networks may not have distinct

physical topologies, are integrated under common operations, and where network segmentation is not required

for availability reasons. It assumes a non-MPLS IP/Ethernet or TDM access being aggregated in a small scale

network.

Figure 8 - Flat LDP Core and Aggregation

2

9 3 2 0 4

Pre-AggregationNode

Pre-AggregationNode

Core andAggregation

IP/MPLS Domain

IGP/LDP Domain

Pre-AggregationNode

Pre-AggregationNode

TDM orPacket Microwave

Mobile Access Ethernet/SDH Fixedand Mobile Access

Pre-AggregationNode

Pre-AggregationNode

IGP Area

CoreNode

CoreNode

CoreNode

CoreNode

Ethernet(SDH)

The small scale aggregation network is assumed to be comprised of core nodes and AGNs that are integrated

in a Single IGP/LDP domain consisting of less than 1000 nodes. Since no segmentation between network layers

exists, a flat LDP LSP provides end-to-end reachability across the network. All mobile (and wireline) services are

enabled by the AGNs. The mobile access is based on TDM and packet microwave links aggregated in AGNs that

provide TDM/ATM/Ethernet VPWS and MPLS VPN transport.

Hierarchical-Labeled BGP LSP Core-Aggregation and Access

This architecture model applies to small geographies. It assumes an MPLS-enabled access network with fiber

and packet microwave links being aggregated in a small scale network.

Figure 9 - Hierarchical-Labeled BGP LSP Core-Aggregation and Access

2 9 3 2 0 5

Pre-AggregationNode

Pre-AggregationNode

Core andAggregation

IP/MPLS Domain

iBGP Hierarchical LSP

Pre-AggregationNode

Pre-AggregationNode

Pre-AggregationNode

Pre-AggregationNode

LDP LSP

IGP Area

CoreNode

CoreNode

CoreNode

CoreNode

AccessIP/MPLSDomain

AccessIP/MPLSDomain

LDP LSP LDP LSP


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The small scale aggregation network is assumed to be comprised of core nodes and AGNs that are integrated

in a single IGP/LDP domain consisting of less than 1000 nodes. The access network is comprised of a separate

IGP domain. The separation can be enabled by making the access network part of a different IGP area from

the aggregation and core nodes, or by running a different IGP process on the PANs corresponding to the

aggregation/core and RAN access networks. LDP is used to build intra-area LSP within each segmented domain

The aggregation/core and access networks are integrated with labeled BGP LSPs, with the PANs acting as ABRs

performing a BGP next-hop-self (NHS) function to extend the iBGP hierarchical LSP across the two domains.

The mobile and wireline services can be enabled by the ANs in the access as well as the PANs/AGNs.

By utilizing BGP community filtering for mobile services and dynamic IP prefix filtering for wireline services, the

ANs perform inbound filtering in BGP in order to learn the required remote destinations for the configured mobile

and wireline services. All other unwanted prefixes are dropped in order to keep the BGP tables small and prevent

unnecessary updates.

Labeled BGP Redistribution into Access IGP

This architecture model applies to networks deployed in small geographies. It assumes an MPLS- enabled

access network with fiber and packet microwave links being aggregated in a small scale network.

Figure 10 - Labeled BGP Redistribution into Access IGP

293

206

Pre-AggregationNode

Pre-AggregationNode

Core andAggregation

IP/MPLS Domain

iBGP Hierarchical LSP

Pre-AggregationNode

Pre-AggregationNode

Pre-AggregationNode

Pre-AggregationNode

Redistributelabeled BGP Service

Communities intoAccess IGP

RedistributeAccess IGP into

labeled BGP

LDP LSP

IGP Area

Redistributelabeled BGP Service

Communities intoAccess IGP


labeled BGP

CoreNode

CoreNode

CoreNode

CoreNode

RANIP/MPLSDomain

RANIP/MPLSDomain

LDP LSP LDP LSP

The network infrastructure organization in this architecture model is the same as the one described in

Hierarchical-Labeled BGP LSP Core-Aggregation and Access. This model differs from the aforementioned

one in that the hierarchical-labeled BGP LSP spans only the combined core/aggregation network and does not

extend to the access domain. Instead of using BGP for inter-domain label distribution in the access domain,

the end-to-end Unified MPLS LSP is extended into the access by using LDP with redistribution. The IGP scale

in the access domain is kept small by selective redistribution of required remote prefixes from iBGP based on

communities. Because there is no mechanism for using dynamic IP prefix lists for filtering in this model, the ANs

support only mobile services. Both mobile and wireline services can be supported by the PANs or AGNs.


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Hierarchical-Labeled BGP LSP Core and Aggregation

This architecture model applies to networks deployed in medium-to-large geographies. It assumes a non-MPLS

IP/Ethernet or TDM access being aggregated in a relatively large scale network.

Figure 11 - Hierarchical-Labeled BGP LSP Core-Aggregation

TDM orPacket Microwave

Mobile Access Ethernet/SDH Fixedand Mobile Access

Ethernet(SDH)

2 9 3 2 0 7

CoreNode

CoreNode

CoreNode

AggregationNode

AggregationNode

CoreNode

Core NetworkIP/MPLS Domain

i/(eBGP) Hierarchical LSP

Aggregation NetworkIP/MPLS Domain

AggregationNode

AggregationNode

AggregationNode

AggregationNode


LDP LSP LDP LSP LDP LSP

The network infrastructure is organized by segmenting the core and aggregation networks into independent IGP/

LDP domains. The segmentation between the core and aggregation domains could be based on a Single AS

Multi-Area design, or utilize a multi-AS design with an inter-AS organization. In the Single AS Multi-Area option,

the separation can be enabled by making the aggregation network part of a different IGP area from the core

network, or by running a different IGP process on the core ABR nodes corresponding to the aggregation and

core networks. The access network is based on native IP or Ethernet links in point-to-point or ring topologies

over fiber and newer Ethernet microwave-based access, or point-to-point TDM+Ethernet links over hybrid

microwave.

All mobile and wireline services are enabled by the AGNs. LDP is used to build intra-area LSP within each

segmented domain. The aggregation and core networks are integrated with labeled BGP LSPs. In the Single AS

Multi-Area option, the core ABRs perform BGP NHS function to extend the iBGP-hierarchical LSP across theaggregation and core domains. When the core and aggregation networks are organized in different ASs, iBGP is

used to build the hierarchical LSP from the PAN to the ASBRs and eBGP is used to extend the end-to-end LSP

across the AS boundary.

BGP community-based egress filtering is performed by the Core Route Reflector (RR) towards the core ABRs,

so that the aggregation networks learn only the required remote destinations for mobile and wireline service

routing, and all unwanted prefixes are dropped. This helps reduce the size of BGP tables on these nodes and

also prevents unnecessary updates.


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Hierarchical-Labeled BGP LSP Core, Aggregation, and Access

This architecture model applies to networks deployed in large geographies. It assumes an MPLS- enabled

access network with fiber and packet microwave links being aggregated in a large scale network.

Figure 12 - Hierarchical-Labeled BGP LSP Core, Aggregation, and Access

2 9 3 2 0 8

CoreNode

CoreNode

CoreNode

AggregationNode

AggregationNode

CoreNode


iBGP (eBGP across ASs) Hierarchical LSP


AggregationNode

AggregationNode

AggregationNode

AggregationNode


AccessIP/MPLSDomain

AccessIP/MPLSDomain

LDP LSPLDP LSP LDP LSP LDP LSP LDP LSP

The network infrastructure is organized by segmenting the core, aggregation, and access networks into

independent IGP/LDP domains. The segmentation between the core, aggregation, and access domains could be

based on a Single AS Multi-Area design or utilize a multi-AS design with an inter-AS organization. In the Single

AS Multi- Area option, the separation between core and aggregation networks can be enabled by making the

aggregation network part of a different IGP area from the core network, or by running a different IGP process on

the core ABR nodes corresponding to the aggregation and core networks. The separation between aggregation

and access networks is typically enabled by running a different IGP process on the PANs corresponding to

the aggregation and access networks. In the inter-AS option, while the core and aggregation networks are

in different ASs, the separation between aggregation and access networks is enabled by making the access

network part of a different IGP area from the aggregation network, or by running a different IGP process on the

PANs corresponding to the aggregation and RAN access networks.

The mobile and wireline services can be enabled by the ANs in the access as well as the PANs and AGNs. LDP

is used to build intra-area LSP within each segmented domain. The access, aggregation, and core networks

are integrated with labeled BGP LSPs. In the Single AS Multi-Area option, the PANs and core ABRs act as ABRs

for their corresponding domains and extend the iBGP hierarchical LSP across the access, aggregation, and

core domains. When the core and aggregation networks are organized in different ASs, the PANs act as ABRs

performing BGP NHS function in order to extend the iBGP hierarchical LSP across the access and aggregation

domains. At the ASBRs, eBGP is used to extend the end-to-end LSP across the AS boundary.

By utilizing BGP community filtering for mobile services and dynamic IP prefix filtering for wireline services, the

ANs perform inbound filtering in BGP in order to learn the required remote destinations for the configured mobile

and wireline services. All other unwanted prefixes are dropped in order to keep the BGP tables small and to

prevent unnecessary updates.


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Hierarchical-Labeled BGP Redistribution into Access IGP

This architecture model applies to networks deployed in large geographies. It assumes an MPLS-enabled access

network with fiber and packet microwave links being aggregated in a large scale network.

Figure 13 - Hierarchical-Labeled BGP Redistribution into Access IGP

293209

Core

Core

Core

Pre-AggregationNode

Pre-AggregationNode

Core


iBGP (eBGP across AS) Hierarchical LSP


Pre-AggregationNode

Pre-AggregationNode

Pre-AggregationNode

Pre-AggregationNode


RANMPLS/IP

RANMPLS/IP

LDP LSP LDP LSP

LDP LSP LDP LSP LDP LSP

IGP Area/Process

IGP Area/Process

Redistribute

labeled BGP ServiceCommunities intoAccess IGP


labeled BGP

Redistribute

labeled BGP ServiceCommunities intoAccess IGP


labeled BGP

The network infrastructure organization in this architecture model is the same as the one described in

Hierarchical-Labeled BGP LSP Core-Aggregation and Access, with options for both Single AS Multi-Area

and Inter-AS designs. This model differs from the aforementioned one in that the hierarchical-labeled BGP LSP

spans only the core and aggregation networks and does not extend to the access domain. Instead of using

BGP for inter-domain label distribution in the access domain, the end-to-end Unified MPLS LSP is extended

into the access by using LDP with redistribution. The IGP scale in the access domain is kept small by selective

redistribution of required remote prefixes from iBGP based on communities. Because there is no mechanism for

using dynamic IP prefix lists for filtering in this model, only mobile services are currently supported by the ANs.

Both mobile and wireline services can be supported by the PANs or AGNs.

Residential Wireline Service ModelsWith network devices becoming increasingly powerful, residential architectures have experienced a shift. The

additional computing capacity and better hardware performances of todays equipment have made multi-service

capabilities within a single network node possible and fueled a transition toward distributed and semi-centralized

models. These new models simplify the architecture by removing the entire IP edge layer. They also reduce

costs by eliminating application-specific nodes, such as dedicated BNGs, and consolidate transport and service

functions within a single device. They allow for optimal placement of the residential service edge based on

subscriber distribution, empowering SPs with the ability to provision subscribers, bandwidth, and service access

according to the specific patterns of their networks.

The readiness of fiber-based access and the consequential increase of bandwidth availability at the last mile

have driven a steep rise in the number of subscribers that can be aggregated at the access layers of the

network. New Ethernet-based access technologies such as PON allow for the aggregation of thousands ofsubscribers on a single AN, with per-subscriber speeds that average 20 Mbps, further justifying the distribution

of subscriber management functions as close as possible to the subscriber-facing edge of the network to satisfy

scale and total bandwidth demands.


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At the same time, the economy of scale and incumbency of legacy access technologies such as DSL, which

is characterized by limited bandwidth and subscriber fan out at the AN, mandate the positioning of subscriber

management functions in a more centralized location. To cater to those needs while guaranteeing Layer-2 like

connectivity between subscribers and subscriber management devices over a scalable transport infrastructure,

operators have abandoned the tra

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