Definitive MPLS Network Designs

• Copyright 2005
• Dimensions: 7-3/8" x 9-1/8"
• Pages: 552
• Edition: 1st

• eBook
• ISBN-10: 0-13-344708-1
• ISBN-13: 978-0-13-344708-8

Field-proven MPLS designs covering MPLS VPNs, pseudowire, QoS, traffic engineering, IPv6, network recovery, and multicast

• Understand technology applications in various service provider and enterprise topologies via detailed design studies
• Benefit from the authors’ vast experience in MPLS network deployment and protocol design
• Visualize real-world solutions through clear, detailed illustrations
• Design studies cover various operator profiles including an interexchange carrier (IXC), a national telco deploying a multiservice backbone carrying Internet and IP VPN services as well as national telephony traffic, an international service provider with many POPs all around the globe, and a large enterprise relying on Layer-3 VPN services to control communications within and across subsidiaries
• Design studies are thoroughly explained through detailed text, sample configurations, and network diagrams

Definitive MPLS Network Designs provides examples of how to combine key technologies at the heart of IP/MPLS networks. Techniques are presented through a set of comprehensive design studies. Each design study is based on characteristics and objectives common to a given profile of network operators having deployed MPLS and discusses all the corresponding design aspects.

The book starts with a technology refresher for each of the technologies involved in the design studies. Next, a series of design studies is presented, each based on a specific hypothetical network representative of service provider and enterprise networks running MPLS. Each design study chapter delivers four elements. They open with a description of the network environment, including the set of supported services, the network topology, the POP structure, the transmission facilities, the basic IP routing design, and possible constraints. Then the chapters present design objectives, such as optimizing bandwidth usage. Following these are details of all aspects of the network design, covering VPN, QoS, TE, network recovery, and—where applicable—multicast, IPv6, and pseudowire. The chapters conclude with a summary of the lessons that can be drawn from the design study so that all types of service providers and large enterprise MPLS architects can adapt aspects of the design solution to their unique network environment and objectives.

Although network architects have many resources for seeking information on the concepts and protocols involved with MPLS, there is no single resource that illustrates how to design a network that optimizes their benefits for a specific operating environment. The variety of network environments and requirements makes it difficult to provide a one-size-fits-all design recommendation. Definitive MPLS Network Designs fills this void.

“This book comes as a boon to professionals who want to understand the power of MPLS and make full use of it.”

-Parantap Lahiri, Manager, IP Network Infrastructure Engineering, MCI

Includes a FREE 45-Day Online Edition

This book is part of the Networking Technology Series from Cisco Press®, which offers networking professionals valuable information for constructing efficient networks, understanding new technologies, and building successful careers.

Table of Contents

Contents

Foreword

Introduction

Chapter 1               Technology Primer: Layer 3 VPN, Multicast VPNs, IPv6, and Pseudowire

MPLS VPN Services in MPLS/IP Networks

Layer 3 MPLS VPN Network Components

Separation of Routing State at PE Routers

Customer-to-Service Provider Routing Exchange

Label Allocation at the PE Router

Advertisement of VPNv4 Routes Across the IP/MPLS Backbone

Import of Remote Routing Information into VRFs

Forwarding of Layer 3 MPLS VPN Packets

Remote Access to the Layer 3 MPLS VPN Service

Dial-in Access Via L2TP VPDN

Dial-in Access Via Direct ISDN

DSL Access Using PPPoA or PPPoE and VPDN (L2TP)

Carrier’s Carrier Architecture

Packet Forwarding with Carrier’s Carrier

Layer 3 MPLS VPN Services Across Autonomous System Boundaries

Inter-AS Back-to-Back VRFs (Option A)

Inter-AS VPNv4 Exchange (Option B)

Inter-AS VPNv4 Exchange Between Route Reflectors (Option C)

Multicast VPNs

Source Distribution Multicast Trees

IP Multicast Shared Trees

Protocol-Independent Multicast (PIM)

PIM Dense Mode (PIM-DM)

PIM Sparse Mode (PIM-SM)

Source-Specific Multicast (SSM)

Multicast Support Within a Layer 3 MPLS VPN

Multicast Domains

mVPN PIM Adjacencies

Multicast Forwarding with mVPN

IPv6 Over MPLS Networks

Overview of IPv6

IPv6 Header

IPv6 Addressing

Neighbor Discovery and Autoconfiguration

IPv6 Routing

IPv6 Quality of Service

IPv6 Security

Deploying IPv6 Over an MPLS Network

IPv6 Provider Edge (6PE)

IPv6 VPN Provider Edge  (6VPE)

Layer 2 Services and Pseudowires

Pseudowire Network Components

Pseudowire Forwarding Equivalent Class

Pseudowire Creation and Signaling

Pseudowire Encapsulation

Pseudowire Packet Flow

Chapter 2               Technology Primer: Quality of Service, Traffic Engineering, and Network Recovery

Quality of Service in MPLS Networks

Traffic Requirements and Service Level Agreements

Application Requirements

Service Level Agreement

QoS Mechanisms

The Fundamental QoS Versus Utilization Curve

The IETF DiffServ Model and Mechanisms

MPLS Support of DiffServ

Combining Tools to Support SLA

Core QoS Engineering

Edge QoS Engineering

QoS Models

Traffic Engineering

MPLS Traffic Engineering Components

Destination

Bandwidth

Affinities

Preemption

Protection by Fast Reroute

Optimized Metric

Hierarchy of Attributes (Set of Ordered Path Option)

TE LSP Path Computation

MPLS TE IGP Routing Extensions

Signaling of a Traffic Engineering LSP

Routing onto a Traffic Engineering LSP

Solving the Fish Problem

TE LSP Deployment Scenarios

Reoptimizing a Traffic Engineering LSP

MPLS Traffic Engineering and Load Balancing

MPLS Traffic Engineering Forwarding Adjacency

Automatic Meshing of a Mesh of TE LSPs 

DiffServ-Aware MPLS Traffic Engineering

Bandwidth Constraints Model

Extensions to the Traffic Engineering LSP Attribute

Extensions to TE LSP Path Computation

Extensions to Traffic Engineering IGP Routing

Extensions to TE LSP Signaling

Routing onto DiffServ-Aware TE LSPs

Example of DS-TE Deployment

MPLS Traffic Engineering in the Context of Multiarea and Multi-AS

Core Network Availability

Protection Versus Restoration

Local Versus Global Recovery

Network Recovery with IP Routing

Use of Dynamic Timers for LSA Origination and SPF Triggering

Computing the Convergence Time with IP Routing

Network Recovery with MPLS Traffic Engineering

MPLS TE Reroute

MPLS TE Path Protection

MPLS TE Fast Reroute

Chapter 3               Interexchange Carrier Design Study

USCom’s Network Environment

USCom’s Network Design Objectives

Routing and Backbone Label Forwarding Design

Separation of Internet and Layer 3 MPLS VPN Services

Internet Service Route Reflection Deployment

Layer 3 MPLS VPN Service Design Overview

PE Router Basic Engineering Guidelines

VRF Naming Convention

Route Distinguisher Allocation

Route Target Allocation for Import/Export Policy

Basic PE Router Configuration Template

PE Router Control-Plane Requirements

PE Router Path MTU Discovery

VPNv4 Route Reflector Deployment Specifics

Deployment Location for VPNv4 Route Reflectors

Preventing Input Drops at the VPNv4 Route Reflectors

PE Router and Route Reflector VPNv4 MP-BGP Peering Template

PE-CE Routing Protocol Design

Static Routing Design Considerations

PE-CE BGP Routing Design Considerations

PE-CE IGP Routing Design Considerations

Specifics of the OSPF Service Deployment

Specifics of the EIGRP Service Deployment 

IP Address Allocation for PE-CE Links

Controlling Route Distribution with Filtering

Security Design for the Layer 3 MPLS VPN Service

Quality of Service Design

SLA for Internet Service

SLA for the Layer 3 MPLS VPN Service

QoS Design in the Core Network

QoS Design on the Network Edge

Traffic Engineering Within the USCom Network

Network Recovery Design

Network Availability Objectives

Operational Constraints on Network Recovery Design

Cost Constraints for the Network Recovery Design

Network Recovery Design for Link Failures

Prefix Prioritization Within the USCom Network

Temporary Loop Avoidance

Forwarding Adjacency for Loop Avoidance

Reuse of a Restored Link

Multiple Failures Within the USCom Network

Link Failure Detection Within the USCom Network

Node Failures Within the USCom Network

Planned Router Maintenance

Unexpected Router Failures

Convergence of IS-IS

IS-IS Failure Detection Time

Flooding of New IS-IS LSPs

Routing Table Computation on Each Node

IS-IS Configuration Within the USCom Network

Design Lessons to Be Taken from USCom

Chapter 4             National Telco Design Study

Telecom Kingland Network Environment

Telecom Kingland POP Structure

Telecom Kingland Design Objectives

Routing and Backbone Label-Forwarding Design

Shared-Edge Internet and Layer 3 MPLS VPN Services

Internet Service: Route Reflection Deployment

Layer 3 MPLS VPN Service: Design Overview

Multiservice PE Router Basic Engineering Guidelines

Customer VRF Naming Convention

RT/RD Allocation Schemes

Network Management VPN 

Load-Balancing Support

iBGP Multipath Support for VPNv4

eiBGP Multipath Support for VPNv4

mPE Router Control-Plane Requirements

VPNv4 Route Reflector Placement

PE-CE Routing Protocol Design

Carrier’s Carrier Service

Load-Balancing Support with Carrier’s Carrier

Large Carrier’s Carrier Customer Attachment Example

Remote Access to the Layer 3 MPLS VPN Service

Dial-In Access Via L2TP VPDN

Dial-In Access Via Direct ISDN

DSL Access Using PPPoE or PPPoA and VPDN (L2TP)

mVPN Service Application

Multicast Address Allocation

Multicast Routing Protocol Support

Rendezvous Point and BSR Design for PIM-SM

Use of Data-MDTs in the mVPN Design

Restricting Multicast Routing State at mPE Routers

Quality of Service Design

Layer 3 MPLS VPN and Internet SLA

QoS Design in the Core Network

QoS Design on the Network Edge for Layer 3 MPLS VPN and Internet

CE Router Egress Policy

mPE Router Ingress Policy

mPE Router Egress Policy

QoS Design on the Network Edge for Voice Trunking

QoS Design on the Network Edge for Layer 3 MPLS VPN CsC

SLA Monitoring and Reporting

MPLS Traffic Engineering Design

Setting the Maximum Reservable Bandwidth on Each MPC Link

TE LSPs Bandwidth

Path Computation

TE LSPs Between PE-PSTN1 Routers

TE LSPs Between PE-PSTN1 and PE-PSTN2 Routers or Between PE-PSTN2 Routers

Reoptimization of TE LSPs

MPLS Traffic Engineering Simulation

TE Scaling Aspects

Use of Refresh Reduction

Provisioning the Mesh of TE LSPs

Monitoring

Last Resort Unconstrained Option 

Network Recovery Design

Network Recovery Design for the Internet and Layer 3 MPLS VPN Traffic

Failure Detection Time

LSA Generation

Failure Notification Time

SPF Triggering

RIB and FIB Updates

OSPF Design Conclusions

Network Recovery Design for the PSTN Traffic

Failure Detection

Set of Backup Tunnels

Backup Tunnel Constraints

Backup Tunnel Design Between Level 1 POPs

Relaxing the SRLG Diversity Constraint

Design of the Backup Tunnels Between Level 2 and Level 1 POPs

Period of Time During Which Backup Tunnels Are in Use

Configuration of a Hold-Off Timer

Failure of a PE-PSTN Router

IPv6 Internet Access Service Design

Design Lessons to Be Taken from Telecom Kingland

Chapter 5              Global Service Provider Design Study

Globenet Network Environment

Globenet Service Portfolio

Globenet POP Network Structure

Type 1 POP Structure

Type 2 POP Structure

Type 3 POP Structure

Globenet Worldwide Network Architecture

EMEA Region

Asia-Pacific Region

North America Region

South America Region

Intercontinental Connectivity

Globenet Routing Architecture

Interoperator Partnerships

Link Types and Protection Details

Design Objectives for the Globenet Network

Layer 3 MPLS VPN Service Design

Shared-Edge Internet and MPLS VPN Services

Connectivity Between Globenet Regions

Filtering VPNv4 Routes at the ASBRs

Route Target/Route Distinguisher Allocation Between Regions

Connectivity with Regional Service Providers 

Providing Internet Services to MPLS VPN Customers

Internet Via the Global or VRF Routing Table

Internet Access Following the Default Route

Full Internet Access Via the PE-CE Access Link

Internet Access Via Globenet NAT/Firewall Services

mVPN Service Design

MP-BGP Support of Inter-AS mVPN

Establishing mVPN MDT Groups Between Globenet Regions

Inter-AS mVPN System Flow

MPLS VPN Security and Scalability

VPN Operational Security

VPN Control Plane Protection

VPN Data Plane Protection

Scaling and Convergence of the Layer 3 MPLS VPN Service

Protocol Interaction

MP-BGP Scaling Considerations

Globenet Routing Convergence Strategy

Layer 3 MPLS VPN Service–Routing Convergence

Tuning the BGP Protocol

Edge Router Capabilities

IPv6 VPN Service Design

IPv6 VPN Design Within a Globenet Region

IPv6 VPN Design Across Globenet Regions

ATM Pseudowire Design

Quality of Service Design

VPN and Internet SLA

QoS Design in the Core Network in the EMEA, AsiaPac, and South America Regions

QoS Design in the Core Network on ATM PVCs

QoS Design in the Core Network in North America

QoS Design in the Core Network Across Regions

QoS Design on the Network Edge for Layer 3 MPLS VPN and Internet

CE Router Egress Policy

PE Router Ingress Policy

PE Router Egress Policy

QoS Design for the Interprovider VPN with Telecom Kingland

QoS Design for Multicast Traffic

QoS Design for the IPv6 VPN

Pseudowire QoS Design for ATM Trunking

SLA Monitoring and Reporting

MPLS Traffic Engineering Design

Setting the Maximum Reservable Bandwidth on Each Link

Automatic Setup and Provisioning of a Full Mesh of TE LSPs 

Dynamic Traffic Engineering LSP Bandwidth Adjustment

Additional Resizing Parameters

Additional Advantages of Dynamic TE LSP Resizing

TE LSP Path Computation

MPLS Traffic Engineering in North America

MPLS Traffic Engineering in the AsiaPac, EMEA, and South America Regions

Reoptimization of TE LSPs

Traffic Engineering Scaling Aspects

Use of Refresh Reduction

Monitoring TE LSPs

Last-Resort Unconstrained Option

TE Design for ATM Pseudowires

Network Recovery Design

MPLS TE Fast Reroute Design Within Globenet Regions

Failure Detection

Set of Backup Tunnels

Backup Tunnel Constraints

Provisioning the Set of Backup Tunnels

Configuring a Hold-Off Timer

IS-IS Routing Design

Failure of a PE Router Supporting ATM Pseudowires

Network Recovery for IPv6 VPN

Virtual POP Design

Conversion of the Johannesburg POP to a VPOP

Attributes of the Inter-AS TE LSPs

Globenet VPOP Migration Strategy

Path Computation for Inter-AS TE LSPs

Reoptimization of Inter-AS TE LSPs

Routing onto Inter-AS TE LSPs

VPOP QoS Design

Recovery of Inter-AS TE LSPs

Policy Control at ASBR Boundaries

Africa Telecom VPOP

Design Lessons to Be Taken from Globenet

Chapter 6               Large Enterprise Design Study

EuroBank’s Network Environment

Description of the Branch Office

Description of an Office Location

Description of a Core Network POP

Description of the Data Centers

Description of the Metro Connections in the UK

EuroBank Design Objectives

EuroBank Network Core Routing Design

Host Routing

Layer 3 MPLS VPN Service Design

Intersubsidiary and DataCenter Connectivity Requirements

Office Location Requirements

EuroBank Group VPN Definitions

Route Target and Route Distinguisher Allocation

Data Center Layer 3 MPLS VPN Design

POP Layer 3 MPLS VPN Design

Core MP-BGP Design

UK Office Location Layer 3 MPLS VPN Design

Routing Within Each Multi-VRF VRF

EuroBank Multicast Deployment and Design

EuroBank Brokerage Encryption Deployment and Design

Layer 3 MPLS VPN Design for VoIP

Architecture of the Managed Telephony Service

On-Net Voice Call Within a EuroBank VPN

On-Net Voice Call Across Two EuroBank VPNs

Layer 3 MPLS VPN Design Within PhoneNet and EuroBank Off-Net Voice Calls

Quality of Service Design

EuroBank’s Service Classes

Traffic Classification in Offices and Data Centers

Sub-100-Mbps QoS Policy

100+Mbps QoS Policy

Gigabit Ethernet Link QoS Policy

QoS Design on the Access for Branches

Traffic Flowing from a Branch

Traffic Flowing to a Branch

Design Lessons to Be Taken from EuroBank

Appendix A             References

Index_                               

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