Software-Defined Wide Area Network Architectures and Technologies

Cover
Half Title
Series Page
Title Page
Copyright Page
Table of Contents
Summary
Introduction
Acknowledgments
Authors
Chapter 1 WAN Developments
	1.1 EVOLUTION OF ENTERPRISE WANs
	1.2 CHALLENGES FACING ENTERPRISE WANs
		1.2.1 Service Cloudification in Full Swing
		1.2.2 Network Virtualization Taking Off
		1.2.3 NaaS as an Inevitable Trend
		1.2.4 Internet-Based Enterprise Communications on the Rise
Chapter 2 Emergence of SD-WAN
	2.1 WHEN WAN AND SDN MEET…
		2.1.1 What Is SDN?
			2.1.1.1 Application Layer
			2.1.1.2 Control Layer
			2.1.1.3 Infrastructure Layer
		2.1.2 SD-WAN Emerges at the Right Time
			2.1.2.1 Gartner
			2.1.2.2 MEF
		Further Reading
	2.2 INTERPRETATION OF SD-WAN
		2.2.1 Fundamental Characteristics of SD-WAN
			2.2.1.1 Hybrid WAN Links, Achieving Flexible Overlay Networking
			2.2.1.2 Device Plug-and-Play, Achieving Fast Service Rollout
			2.2.1.3 High-Performance Branch Devices, Achieving Application-Centric Full-Service Processing
			2.2.1.4 Service Intent-Oriented Network Orchestration and Automated Service Rollout
			2.2.1.5 On-Demand, Efficient Cloud Connectivity
			2.2.1.6 Intelligent Traffic Steering, Guaranteeing Application Experience
			2.2.1.7 WAN Optimization, Improving WAN Transmission Quality
			2.2.1.8 Secure, Reliable Connectivity
			2.2.1.9 Centralized, Visualized Management and Control, Facilitating O&M
			2.2.1.10 Open Northbound APIs, Implementing Programmable SD-WAN
		2.2.2 Core Benefits of SD-WAN
			2.2.2.1 Robust Connectivity: Flexible Networking, Building On-Demand Multi-cloud and Multi-network Connectivity
			2.2.2.2 Superior Experience: Application-Based Traffic Steering and Optimization, Ensuring High-Quality Experience of Key Applications
			2.2.2.3 High Performance: Superb Branch Devices, Ideal for Building a New Forwarding Engine
			2.2.2.4 Easy O&M: Intent-Driven, Simplified Network O&M for Branches
Chapter 3 Introduction to the SD-WAN Solution
	3.1 SD-WAN SOLUTION
		3.1.1 SD-WAN Architecture Design
			3.1.1.1 Network Layer
			3.1.1.2 Control Layer
			3.1.1.3 Service Layer
		3.1.2 Key Interaction Interfaces and Protocols
			3.1.2.1 Management Channel
			3.1.2.2 Control Channel
			3.1.2.3 Data Channel
			3.1.2.4 YANG Model
			3.1.2.5 RESTful API
		3.1.3 Key Service Processes
	3.2 BUSINESS MODELS OF SD-WAN
		3.2.1 Definition of Business Roles
			3.2.1.1 SD-WAN Solution Provider
			3.2.1.2 End Users of the SD-WAN Solution
			3.2.1.3 SD-WAN Service Provider
		3.2.2 Carrier/MSP Resale Model
			3.2.2.1 Multi-tenant Management
			3.2.2.2 IWG
			3.2.2.3 POP Networking
			3.2.2.4 VAS
			3.2.2.5 IPv6
			3.2.2.6 Northbound Open APIs, Easy to Integrate
		3.2.3 Enterprise-Built Model
	3.3 PANORAMA OF THE SD-WAN SOLUTION
		3.3.1 Networking Sub-solution
		3.3.2 Application Experience Sub-solution
		3.3.3 Security Sub-solution
		3.3.4 O&M Sub-solution
Chapter 4 Starting from Sites
	4.1 SITE TYPES
	4.2 CPE: “SPOKESPERSON” OF SITES
		4.2.1 Diverse CPE Forms
		4.2.2 CPE: Connecting Sites
			4.2.2.1 WAN-Side Connection
			4.2.2.2 LAN-Side Connection
		4.2.3 Dual-Gateway Interconnection
	4.3 KEY CAPABILITIES OF CPEs
		4.3.1 Traditional CPE
		4.3.2 Convergent CPE
		4.3.3 SD-WAN CPE
	4.4 CPE PLUG AND PLAY
		4.4.1 Fundamentals
			4.4.1.1 A CPE Connects to a WAN
			4.4.1.2 The CPE Connects to the SDN Controller
			4.4.1.3 The SDN Controller Delivers Configurations
		4.4.2 Deployment Practices
			4.4.2.1 Email-Based Deployment
			4.4.2.2 Registration Center-Based Deployment
			4.4.2.3 USB-Based Deployment
			4.4.2.4 DHCP-Based Deployment
Chapter 5 Site Interconnection
	5.1 SD-WAN NETWORKING OVERVIEW
		5.1.1 Networking Scenario Analysis
		5.1.2 Networking Design Principles
	5.2 OVERLAY NETWORK DESIGN
		5.2.1 Diversified Network Topologies
			5.2.1.1 Single-Layer Network Topology
			5.2.1.2 Hierarchical Network Topology
		5.2.2 SD-WAN Network Model
			5.2.2.1 MEF-Defined SD-WAN Network Model
			5.2.2.2 Huawei’s Definition of the SD-WAN Network Model
		5.2.3 VPN Design
			5.2.3.1 VPN Isolation at Sites
			5.2.3.2 VPN Isolation in Tunnels
		5.2.4 Tunnel Design
			5.2.4.1 SD-WAN Tunnel Design Principles
			5.2.4.2 IP Overlay Tunnel Technology
		5.2.5 Routing Design
			5.2.5.1 EVPN Fundamentals
			5.2.5.2 EVPN-Based Enhanced SD-WAN Routing Solution
	5.3 NETWORK RELIABILITY DESIGN
		5.3.1 Network Link Reliability Design
			5.3.1.1 Full Interconnection between CPEs and the Underlay Network
			5.3.1.2 Each CPE Connects to Only One Underlay Network
		5.3.2 Network Device Reliability Design
		5.3.3 Core Site Reliability Design
			5.3.3.1 Hub Site Redundancy Design
			5.3.3.2 Redirect Site Redundancy Design
	5.4 NETWORK ORCHESTRATION AND AUTOMATION
		5.4.1 Fundamentals of Network Orchestration
			5.4.1.1 Point: Abstraction of Single-Point NE Functions
			5.4.1.2 Line: Abstraction of Network Connectivity Functions
			5.4.1.3 Plane: Abstraction of Networking Functions
		5.4.2 Tunnel Orchestration
			5.4.2.1 Overlay Tunnel Establishment
			5.4.2.2 Examples of Overlay Tunnel Orchestration
		5.4.3 Topology Orchestration
			5.4.3.1 Hub-Spoke
			5.4.3.2 Full-Mesh
			5.4.3.3 Partial-Mesh
			5.4.3.4 Hierarchical
	5.5 INTERNET ACCESS
		5.5.1 Local Internet Access
		5.5.2 Centralized Internet Access
			5.5.2.1 Intra-area Centralized Internet Access
			5.5.2.2 Global Centralized Internet Access
		5.5.3 Hybrid Internet Access
	5.6 WAN NAT TRAVERSAL
		5.6.1 NAT Mapping and Filtering
			5.6.1.1 Full Cone NAT
			5.6.1.2 Restricted Cone NAT
			5.6.1.3 Port-Restricted Cone NAT
			5.6.1.4 Symmetric NAT
		5.6.2 NAT Detection and Hole Punching
	5.7 INTERCONNECTION WITH LEGACY SITES
		5.7.1 Interconnection through an SD-WAN Site
			5.7.1.1 Back-to-Back Interconnection
			5.7.1.2 Local Interconnection
		5.7.2 Interconnection through an IWG
			5.7.2.1 Option A
			5.7.2.2 Option B
			5.7.2.3 Reliability Design
	5.8 POP NETWORKING
		5.8.1 Concepts and Principles
		5.8.2 Solution Design
			5.8.2.1 POP Gateway
			5.8.2.2 Site
		5.8.3 Solution Highlights
	5.9 FLEXIBLE CONNECTION TO PUBLIC CLOUDS
		5.9.1 Cloud Concepts and Basic Principles
		5.9.2 Cloud-Network Synergy Scenario Analysis
			5.9.2.1 Connecting Branch Sites to the Public Cloud
			5.9.2.2 Hybrid Cloud
		5.9.3 Public Cloud Connection Solution
			5.9.3.1 IPsec VPN Gateway Solution
			5.9.3.2 vCPE Cloud Site Solution
			5.9.3.3 Multi-tenant Cloud Gateway Solution
		5.9.4 Hybrid Cloud Solution
			5.9.4.1 Interconnection between Private and Public Clouds
			5.9.4.2 Heterogeneous Public Cloud Interconnection
Chapter 6 Guaranteed Application Experience
	6.1 ASSURANCE SOLUTION
	6.2 APPLICATION IDENTIFICATION
		6.2.1 Application Classification
			6.2.1.1 Production Applications
			6.2.1.2 Collaboration Applications
			6.2.1.3 Cloud Applications
			6.2.1.4 Entertainment Applications
		6.2.2 FPI
			6.2.2.1 Protocol Identification
			6.2.2.2 DNS Correlation Identification
		6.2.3 SA
			6.2.3.1 Packet Signature Identification
			6.2.3.2 Correlation Identification
			6.2.3.3 Behavior Identification
			6.2.3.4 Network-Wide Synchronous Identification
	6.3 APPLICATION-BASED TRAFFIC STEERING
		6.3.1 Traffic Steering Scenarios
			6.3.1.1 Link Quality-Based Traffic Steering
			6.3.1.2 Link Load-Based Traffic Steering
			6.3.1.3 Application Priority-Based Traffic Steering
		6.3.2 Quality Detection
			6.3.2.1 Packet Loss Rate
			6.3.2.2 Two-Way Latency
			6.3.2.3 Jitter
		6.3.3 Traffic Steering Policy
			6.3.3.1 Configuring Traffic Steering Policies
			6.3.3.2 Updating Traffic Steering Policies
			6.3.3.3 Applying Traffic Steering Policies
		6.3.4 Configuration Practices
	6.4 QoS SOLUTION
		6.4.1 Overall Solution
			6.4.1.1 Site-to-Site Rate Limiting
			6.4.1.2 Site-to-Gateway Rate Limiting
		6.4.2 Site-to-Site Rate Limiting
			6.4.2.1 QoS Implementation in the Outbound Direction
			6.4.2.2 QoS Implementation in the Inbound Direction
		6.4.3 Site-to-Gateway Rate Limiting
			6.4.3.1 Site-to-IWG Rate Limiting
			6.4.3.2 Site-to-POP Gateway Rate Limiting
	6.5 WAN OPTIMIZATION
		6.5.1 Conventional WAN Optimization Solutions
			6.5.1.1 Packet Loss Mitigation
			6.5.1.2 Transmission Optimization
			6.5.1.3 Data Optimization
			6.5.1.4 Application Protocol Optimization
		6.5.2 Packet Loss Mitigation Technologies
			6.5.2.1 FEC Algorithm: Recovers Lost Packets
			6.5.2.2 A-FEC: Automatically Adjusts the Redundancy Rate
			6.5.2.3 Multi-Path Packet Replication: Mitigates Packet Loss
			6.5.2.4 Multi-Path FEC: Mitigates Packet Loss
		6.5.3 Transmission Optimization Technologies
			6.5.3.1 Why Is Optimization for TCP-Based Transmission Necessary?
			6.5.3.2 BBR: Optimization at the Transmit End
			6.5.3.3 FillP: Dual-End Optimization
		6.5.4 Third-Party WAN Optimization Technologies
			6.5.4.1 Data Deduplication and Compression
			6.5.4.2 Optimization Technologies for Web Pages and Web-Based Applications
			6.5.4.3 Optimization Technologies for File Transfer and Database Access Protocols
			6.5.4.4 Video Optimization Technologies
			6.5.4.5 SaaS Application Optimization Technologies
	6.6 INTENT-DRIVEN APPLICATION EXPERIENCE OPTIMIZATION
		6.6.1 Experience Optimization
		6.6.2 Centralized Configuration Approach
		6.6.3 Convergent Scheduling Approach
Chapter 7 Security: Top Priority
	7.1 NEW SECURITY CHALLENGES
	7.2 SYSTEM SECURITY
		7.2.1 Component Security
			7.2.1.1 SDN Controller
			7.2.1.2 CPE
		7.2.2 Inter-component Communication Security
			7.2.2.1 Basic Principles of Authentication, Encryption, and Verification
			7.2.2.2 Access Authentication Based on Zero Trust
			7.2.2.3 Data Protection Using Secure Communication Protocols
			7.2.2.4 Security Isolation in a Multi-tenant Scenario
	7.3 SERVICE SECURITY
		7.3.1 Site-to-Site
		7.3.2 Site-to-Internet
			7.3.2.1 Built-in Security Functions of CPEs
			7.3.2.2 VAS-Based Advanced Security Protection Functions of uCPEs
		7.3.3 Site-to-Cloud
Chapter 8 Easy O&M
	8.1 O&M MODE TRANSFORMATION
	8.2 O&M ARCHITECTURE
	8.3 O&M PERMISSION CONTROL
		8.3.1 O&M Mode and Management Roles
			8.3.1.1 System Administrator
			8.3.1.2 MSP Administrator
			8.3.1.3 Tenant Administrator
		8.3.2 Role-Based Permission Control
	8.4 NETWORK-WIDE MONITORING CAPABILITIES
		8.4.1 Dashboard View
		8.4.2 Network-Wide Monitoring
			8.4.2.1 Alarm Monitoring
			8.4.2.2 Overlay Network Topology Monitoring
			8.4.2.3 Site Monitoring
			8.4.2.4 Inter-site Monitoring
		8.4.3 Quality Prediction
			8.4.3.1 Link-Based Network Quality Prediction
			8.4.3.2 Application-Based Network Quality Prediction
	8.5 FAULT LOCATING ASSISTANT
		8.5.1 Diagnosis Tools
			8.5.1.1 Application Quality Diagnosis
			8.5.1.2 Network Diagnosis
			8.5.1.3 Device Diagnosis
		8.5.2 Device Maintenance
			8.5.2.1 Device Upgrade and Downgrade
			8.5.2.2 Device Replacement
		8.5.3 Log Management
		8.5.4 Intelligent Troubleshooting
	8.6 MIGRATION FROM TRADITIONAL NETWORKS TO SD-WAN
		8.6.1 Headquarters/DC Site Migration
			8.6.1.1 Connecting a Single SD-WAN CPE in Off-Path Mode
			8.6.1.2 Connecting Two SD-WAN CPEs in Off-Path Mode
		8.6.2 Branch Site Migration
			8.6.2.1 Directly Replacing or Upgrading a Legacy CE
			8.6.2.2 Connecting SD-WAN CPEs in Off-Path Mode
Chapter 9 SD-WAN Best Practices
	9.1 SD-WAN APPLICATION SCENARIOS
	9.2 TYPICAL SD-WAN CASES
		9.2.1 SD-WAN in Finance
			9.2.1.1 Scenario Analysis
			9.2.1.2 Solution Design
		9.2.2 SD-WAN in Large Enterprises
			9.2.2.1 Scenario Analysis
			9.2.2.2 Solution Design
		9.2.3 SD-WAN in Carriers
			9.2.3.1 Scenario Analysis
			9.2.3.2 Solution Design
		9.2.4 SD-WAN in MSPs
			9.2.4.1 Scenario Analysis
			9.2.4.2 Solution Design
Chapter 10 SD-WAN Components
	10.1 NETENGINE AR SERIES ROUTERS
		10.1.1 Overview
		10.1.2 Application Scenarios
			10.1.2.1 Constructing SD-WAN Using Hybrid Links
			10.1.2.2 Building Different Types of VPNs over the Internet
		10.1.3 Functions and Features
			10.1.3.1 High Performance
			10.1.3.2 High Reliability
			10.1.3.3 Easy O&M
			10.1.3.4 Service Integration
			10.1.3.5 Security
			10.1.3.6 SD-WAN Ready
	10.2 IMASTER NCE-WAN
		10.2.1 Introduction
		10.2.2 Technical Highlights
			10.2.2.1 Fast Deployment Accelerates SD-WAN Service Rollouts
			10.2.2.2 Intelligent Traffic Steering Improves Service Experience
			10.2.2.3 On-Demand VASs Speed Up Service Provisioning
			10.2.2.4 Visualized O&M Offers Network-Wide Application Traffic Visibility
		10.2.3 Functions and Features
			10.2.3.1 Plug-and-Play
			10.2.3.2 Tunnel Management
			10.2.3.3 Intelligent Traffic Steering
			10.2.3.4 On-Demand VASs
			10.2.3.5 Visualized O&M
			10.2.3.6 Performance Monitoring
			10.2.3.7 Log Management
Chapter 11 SD-WAN Outlook
	11.1 TECHNOLOGY EVOLUTION
		11.1.1 5G
			11.1.1.1 Scenario 1: “5G + SD-WAN” for Unstaffed Bank Branches
			11.1.1.2 Scenario 2: “5G + SD-WAN” for Smart Bank Branch Interconnection
		11.1.2 SRv6
			11.1.2.1 SR Overview
			11.1.2.2 SRv6 Overview
		11.1.3 AI
	11.2 NEW INDUSTRY CHANGES
	11.3 REVIEW AND PROSPECT
ACRONYMS AND ABBREVIATIONS
REFERENCES