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Definitive MPLS Network Designs

Book Description

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

    1. Copyright
      1. Dedications
    2. About the Authors
    3. About the Technical Reviewers
    4. Acknowledgments
    5. Command Syntax Conventions
    6. Foreword
    7. Introduction
      1. How this Book is Organized
      2. Who Should Read This Book
    8. 1. Technology Primer: Layer 3 VPN, Multicast VPNs, IPv6, and Pseudowire
      1. MPLS VPN Services in MPLS/IP Networks
        1. Layer 3 MPLS VPN Network Components
        2. Separation of Routing State at PE Routers
        3. Customer-to-Service Provider Routing Exchange
        4. Label Allocation at the PE Router
        5. Advertisement of VPNv4 Routes Across the IP/MPLS Backbone
        6. Import of Remote Routing Information into VRFs
        7. Forwarding of Layer 3 MPLS VPN Packets
      2. Remote Access to the Layer 3 MPLS VPN Service
        1. Dial-in Access Via L2TP VPDN
        2. Dial-in Access Via Direct ISDN
        3. DSL Access Using PPPoA or PPPoE and VPDN (L2TP)
      3. Carrier’s Carrier Architecture
        1. Packet Forwarding with Carrier’s Carrier
      4. Layer 3 MPLS VPN Services Across Autonomous System Boundaries
        1. Inter-AS Back-to-Back VRFs (Option A)
        2. Inter-AS VPNv4 Exchange (Option B)
        3. Inter-AS VPNv4 Exchange Between Route Reflectors (Option C)
      5. Multicast VPNs
        1. Source Distribution Multicast Trees
        2. IP Multicast Shared Trees
        3. Protocol-Independent Multicast (PIM)
          1. PIM Dense Mode (PIM-DM)
          2. PIM Sparse Mode (PIM-SM)
        4. Source-Specific Multicast (SSM)
        5. Multicast Support Within a Layer 3 MPLS VPN
        6. Multicast Domains
        7. mVPN PIM Adjacencies
        8. Multicast Forwarding with mVPN
      6. IPv6 Over MPLS Networks
        1. Overview of IPv6
          1. IPv6 Header
          2. IPv6 Addressing
          3. Neighbor Discovery and Autoconfiguration
          4. IPv6 Routing
          5. IPv6 Quality of Service
          6. IPv6 Security
        2. Deploying IPv6 Over an MPLS Network
        3. IPv6 Provider Edge (6PE)
        4. IPv6 VPN Provider Edge (6VPE)
      7. Layer 2 Services and Pseudowires
        1. Pseudowire Network Components
          1. Pseudowire Forwarding Equivalent Class
        2. Pseudowire Creation and Signaling
        3. Pseudowire Encapsulation
        4. Pseudowire Packet Flow
    9. 2. Technology Primer: Quality of Service, Traffic Engineering, and Network Recovery
      1. Quality of Service in MPLS Networks
        1. Traffic Requirements and Service Level Agreements
          1. Application Requirements
          2. Service Level Agreement
        2. QoS Mechanisms
        3. The Fundamental QoS Versus Utilization Curve
        4. The IETF DiffServ Model and Mechanisms
        5. MPLS Support of DiffServ
        6. Combining Tools to Support SLA
          1. Core QoS Engineering
          2. Edge QoS Engineering
          3. QoS Models
      2. Traffic Engineering
        1. MPLS Traffic Engineering Components
          1. Destination
          2. Bandwidth
          3. Affinities
          4. Preemption
          5. Protection by Fast Reroute
          6. Optimized Metric
        2. Hierarchy of Attributes (Set of Ordered Path Option)
        3. TE LSP Path Computation
        4. MPLS TE IGP Routing Extensions
        5. Signaling of a Traffic Engineering LSP
        6. Routing onto a Traffic Engineering LSP
        7. Solving the Fish Problem
        8. TE LSP Deployment Scenarios
        9. Reoptimizing a Traffic Engineering LSP
        10. MPLS Traffic Engineering and Load Balancing
        11. MPLS Traffic Engineering Forwarding Adjacency
        12. Automatic Meshing of a Mesh of TE LSPs
      3. DiffServ-Aware MPLS Traffic Engineering
        1. Bandwidth Constraints Model
        2. Extensions to the Traffic Engineering LSP Attribute
        3. Extensions to TE LSP Path Computation
        4. Extensions to Traffic Engineering IGP Routing
        5. Extensions to TE LSP Signaling
        6. Routing onto DiffServ-Aware TE LSPs
        7. Example of DS-TE Deployment
      4. MPLS Traffic Engineering in the Context of Multiarea and Multi-AS
      5. Core Network Availability
        1. Protection Versus Restoration
        2. Local Versus Global Recovery
        3. Network Recovery with IP Routing
        4. Use of Dynamic Timers for LSA Origination and SPF Triggering
          1. Computing the Convergence Time with IP Routing
        5. Network Recovery with MPLS Traffic Engineering
          1. MPLS TE Reroute
          2. MPLS TE Path Protection
          3. MPLS TE Fast Reroute
            1. Mode of Operation Before Failure
            2. Mode of Operation During and After Failure
            3. Number of NNHOP Backup Tunnels Required by Fast Reroute Backup
            4. Backup Tunnel Path Computation
            5. Backup Tunnel Load Balancing
            6. Revertive Versus Nonrevertive
            7. Fast Reroute Summary
    10. 3. Interexchange Carrier Design Study
      1. USCom’s Network Environment
      2. USCom’s Network Design Objectives
      3. Routing and Backbone Label Forwarding Design
        1. Separation of Internet and Layer 3 MPLS VPN Services
        2. Internet Service Route Reflection Deployment
      4. Layer 3 MPLS VPN Service Design Overview
        1. PE Router Basic Engineering Guidelines
          1. VRF Naming Convention
          2. Route Distinguisher Allocation
          3. Route Target Allocation for Import/Export Policy
          4. Basic PE Router Configuration Template
        2. PE Router Control-Plane Requirements
          1. PE Router Path MTU Discovery
        3. VPNv4 Route Reflector Deployment Specifics
          1. Deployment Location for VPNv4 Route Reflectors
          2. Preventing Input Drops at the VPNv4 Route Reflectors
          3. PE Router and Route Reflector VPNv4 MP-BGP Peering Template
        4. PE-CE Routing Protocol Design
          1. Static Routing Design Considerations
          2. PE-CE BGP Routing Design Considerations
          3. PE-CE IGP Routing Design Considerations
          4. Specifics of the OSPF Service Deployment
          5. Specifics of the EIGRP Service Deployment
        5. IP Address Allocation for PE-CE Links
        6. Controlling Route Distribution with Filtering
        7. Security Design for the Layer 3 MPLS VPN Service
      5. Quality of Service Design
        1. SLA for Internet Service
        2. SLA for the Layer 3 MPLS VPN Service
        3. QoS Design in the Core Network
        4. QoS Design on the Network Edge
      6. Traffic Engineering Within the USCom Network
      7. Network Recovery Design
        1. Network Availability Objectives
        2. Operational Constraints on Network Recovery Design
        3. Cost Constraints for the Network Recovery Design
        4. Network Recovery Design for Link Failures
        5. Prefix Prioritization Within the USCom Network
        6. Temporary Loop Avoidance
          1. Forwarding Adjacency for Loop Avoidance
        7. Reuse of a Restored Link
        8. Multiple Failures Within the USCom Network
        9. Link Failure Detection Within the USCom Network
        10. Node Failures Within the USCom Network
          1. Planned Router Maintenance
          2. Unexpected Router Failures
        11. Convergence of IS-IS
          1. IS-IS Failure Detection Time
          2. Flooding of New IS-IS LSPs
          3. Routing Table Computation on Each Node
        12. IS-IS Configuration Within the USCom Network
      8. Design Lessons to Be Taken from USCom
    11. 4. National Telco Design Study
      1. Telecom Kingland Network Environment
        1. Telecom Kingland POP Structure
      2. Telecom Kingland Design Objectives
      3. Routing and Backbone Label-Forwarding Design
        1. Shared-Edge Internet and Layer 3 MPLS VPN Services
        2. Internet Service: Route Reflection Deployment
      4. Layer 3 MPLS VPN Service: Design Overview
        1. Multiservice PE Router Basic Engineering Guidelines
        2. Customer VRF Naming Convention
        3. RT/RD Allocation Schemes
        4. Network Management VPN
        5. Load-Balancing Support
          1. iBGP Multipath Support for VPNv4
          2. eiBGP Multipath Support for VPNv4
        6. mPE Router Control-Plane Requirements
          1. VPNv4 Route Reflector Placement
        7. PE-CE Routing Protocol Design
      5. Carrier’s Carrier Service
        1. Load-Balancing Support with Carrier’s Carrier
        2. Large Carrier’s Carrier Customer Attachment Example
      6. Remote Access to the Layer 3 MPLS VPN Service
        1. Dial-In Access Via L2TP VPDN
        2. Dial-In Access Via Direct ISDN
        3. DSL Access Using PPPoE or PPPoA and VPDN (L2TP)
      7. mVPN Service Application
        1. Multicast Address Allocation
        2. Multicast Routing Protocol Support
        3. Rendezvous Point and BSR Design for PIM-SM
        4. Use of Data-MDTs in the mVPN Design
        5. Restricting Multicast Routing State at mPE Routers
      8. Quality of Service Design
        1. Layer 3 MPLS VPN and Internet SLA
        2. QoS Design in the Core Network
        3. QoS Design on the Network Edge for Layer 3 MPLS VPN and Internet
          1. CE Router Egress Policy
          2. mPE Router Ingress Policy
          3. mPE Router Egress Policy
        4. QoS Design on the Network Edge for Voice Trunking
        5. QoS Design on the Network Edge for Layer 3 MPLS VPN CsC
        6. SLA Monitoring and Reporting
      9. MPLS Traffic Engineering Design
        1. Setting the Maximum Reservable Bandwidth on Each MPC Link
        2. TE LSPs Bandwidth
        3. Path Computation
        4. TE LSPs Between PE-PSTN1 Routers
        5. TE LSPs Between PE-PSTN1 and PE-PSTN2 Routers or Between PE-PSTN2 Routers
        6. Reoptimization of TE LSPs
        7. MPLS Traffic Engineering Simulation
        8. TE Scaling Aspects
        9. Use of Refresh Reduction
        10. Provisioning the Mesh of TE LSPs
        11. Monitoring
        12. Last Resort Unconstrained Option
      10. Network Recovery Design
        1. Network Recovery Design for the Internet and Layer 3 MPLS VPN Traffic
          1. Failure Detection Time
          2. LSA Generation
          3. Failure Notification Time
          4. SPF Triggering
          5. RIB and FIB Updates
          6. OSPF Design Conclusions
        2. Network Recovery Design for the PSTN Traffic
          1. Failure Detection
          2. Set of Backup Tunnels
          3. Backup Tunnel Constraints
          4. Backup Tunnel Design Between Level 1 POPs
          5. Relaxing the SRLG Diversity Constraint
          6. Design of the Backup Tunnels Between Level 2 and Level 1 POPs
          7. Period of Time During Which Backup Tunnels Are in Use
          8. Configuration of a Hold-Off Timer
          9. Failure of a PE-PSTN Router
      11. IPv6 Internet Access Service Design
      12. Design Lessons to Be Taken from Telecom Kingland
    12. 5. Global Service Provider Design Study
      1. Globenet Network Environment
        1. Globenet Service Portfolio
        2. Globenet POP Network Structure
          1. Type 1 POP Structure
          2. Type 2 POP Structure
          3. Type 3 POP Structure
        3. Globenet Worldwide Network Architecture
          1. EMEA Region
          2. Asia-Pacific Region
          3. North America Region
          4. South America Region
        4. Intercontinental Connectivity
        5. Globenet Routing Architecture
        6. Interoperator Partnerships
        7. Link Types and Protection Details
      2. Design Objectives for the Globenet Network
      3. Layer 3 MPLS VPN Service Design
        1. Shared-Edge Internet and MPLS VPN Services
        2. Connectivity Between Globenet Regions
          1. Filtering VPNv4 Routes at the ASBRs
          2. Route Target/Route Distinguisher Allocation Between Regions
        3. Connectivity with Regional Service Providers
      4. Providing Internet Services to MPLS VPN Customers
        1. Internet Via the Global or VRF Routing Table
        2. Internet Access Following the Default Route
        3. Full Internet Access Via the PE-CE Access Link
        4. Internet Access Via Globenet NAT/Firewall Services
      5. mVPN Service Design
        1. MP-BGP Support of Inter-AS mVPN
        2. Establishing mVPN MDT Groups Between Globenet Regions
        3. Inter-AS mVPN System Flow
      6. MPLS VPN Security and Scalability
        1. VPN Operational Security
        2. VPN Control Plane Protection
        3. VPN Data Plane Protection
        4. Scaling and Convergence of the Layer 3 MPLS VPN Service
          1. Protocol Interaction
          2. MP-BGP Scaling Considerations
        5. Globenet Routing Convergence Strategy
          1. Layer 3 MPLS VPN Service—Routing Convergence
          2. Tuning the BGP Protocol
        6. Edge Router Capabilities
      7. IPv6 VPN Service Design
        1. IPv6 VPN Design Within a Globenet Region
        2. IPv6 VPN Design Across Globenet Regions
      8. ATM Pseudowire Design
      9. Quality of Service Design
        1. VPN and Internet SLA
        2. QoS Design in the Core Network in the EMEA, AsiaPac, and South America Regions
          1. QoS Design in the Core Network on ATM PVCs
        3. QoS Design in the Core Network in North America
        4. QoS Design in the Core Network Across Regions
        5. QoS Design on the Network Edge for Layer 3 MPLS VPN and Internet
          1. CE Router Egress Policy
          2. PE Router Ingress Policy
          3. PE Router Egress Policy
        6. QoS Design for the Interprovider VPN with Telecom Kingland
        7. QoS Design for Multicast Traffic
        8. QoS Design for the IPv6 VPN
        9. Pseudowire QoS Design for ATM Trunking
        10. SLA Monitoring and Reporting
      10. MPLS Traffic Engineering Design
        1. Setting the Maximum Reservable Bandwidth on Each Link
        2. Automatic Setup and Provisioning of a Full Mesh of TE LSPs
        3. Dynamic Traffic Engineering LSP Bandwidth Adjustment
          1. Additional Resizing Parameters
          2. Additional Advantages of Dynamic TE LSP Resizing
        4. TE LSP Path Computation
        5. MPLS Traffic Engineering in North America
        6. MPLS Traffic Engineering in the AsiaPac, EMEA, and South America Regions
        7. Reoptimization of TE LSPs
        8. Traffic Engineering Scaling Aspects
        9. Use of Refresh Reduction
        10. Monitoring TE LSPs
        11. Last-Resort Unconstrained Option
        12. TE Design for ATM Pseudowires
      11. Network Recovery Design
        1. MPLS TE Fast Reroute Design Within Globenet Regions
          1. Failure Detection
        2. Set of Backup Tunnels
          1. Backup Tunnel Constraints
          2. Provisioning the Set of Backup Tunnels
          3. Configuring a Hold-Off Timer
          4. IS-IS Routing Design
        3. Failure of a PE Router Supporting ATM Pseudowires
        4. Network Recovery for IPv6 VPN
      12. Virtual POP Design
        1. Conversion of the Johannesburg POP to a VPOP
        2. Attributes of the Inter-AS TE LSPs
        3. Globenet VPOP Migration Strategy
          1. Path Computation for Inter-AS TE LSPs
        4. Reoptimization of Inter-AS TE LSPs
        5. Routing onto Inter-AS TE LSPs
        6. VPOP QoS Design
        7. Recovery of Inter-AS TE LSPs
        8. Policy Control at ASBR Boundaries
        9. Africa Telecom VPOP
      13. Design Lessons to Be Taken from Globenet
    13. 6. Large Enterprise Design Study
      1. EuroBank’s Network Environment
        1. Description of the Branch Office
        2. Description of an Office Location
        3. Description of a Core Network POP
        4. Description of the Data Centers
        5. Description of the Metro Connections in the UK
      2. EuroBank Design Objectives
      3. EuroBank Network Core Routing Design
        1. Host Routing
      4. Layer 3 MPLS VPN Service Design
        1. Intersubsidiary and DataCenter Connectivity Requirements
        2. Office Location Requirements
        3. EuroBank Group VPN Definitions
          1. Route Target and Route Distinguisher Allocation
        4. Data Center Layer 3 MPLS VPN Design
        5. POP Layer 3 MPLS VPN Design
        6. Core MP-BGP Design
        7. UK Office Location Layer 3 MPLS VPN Design
        8. Routing Within Each Multi-VRF VRF
        9. EuroBank Multicast Deployment and Design
        10. EuroBank Brokerage Encryption Deployment and Design
      5. Layer 3 MPLS VPN Design for VoIP
        1. Architecture of the Managed Telephony Service
        2. On-Net Voice Call Within a EuroBank VPN
        3. On-Net Voice Call Across Two EuroBank VPNs
        4. Layer 3 MPLS VPN Design Within PhoneNet and EuroBank Off-Net Voice Calls
      6. Quality of Service Design
        1. EuroBank’s Service Classes
        2. Traffic Classification in Offices and Data Centers
        3. Sub-100-Mbps QoS Policy
        4. 100+ Mbps QoS Policy
        5. Gigabit Ethernet Link QoS Policy
        6. QoS Design on the Access for Branches
          1. Traffic Flowing from a Branch
          2. Traffic Flowing to a Branch
      7. Design Lessons to Be Taken from EuroBank
    14. A. References