About the Book

Today, networks must evolve and scale faster than ever. You can’t manage everything by hand anymore: You need to automate relentlessly. YANG, along with the NETCONF, RESTCONF, or gRPC/gNMI protocols, is the most practical solution, but most implementers have had to learn by trial and error. Now, Network Programmability with YANG gives you complete and reliable guidance for unlocking the full power of network automation using model-driven APIs and protocols.
Authored by three YANG pioneers, this plain-spoken book guides you through successfully applying software practices based on YANG data models. The authors focus on the network operations layer, emphasizing model-driven APIs, and underlying transports.
Whether you’re a network operator, DevOps engineer, software developer, orchestration engineer, NMS/OSS architect, service engineer, or manager, this guide can help you dramatically improve value, agility, and manageability throughout your network.

• Discover the value of implementing YANG and Data Model-Driven Management in your network
• Explore the layers and components of a complete working solution
• Build a business case where value increases as your solution grows
• Drill down into transport protocols: NETCONF, RESTCONF, and gNMI/gRPC
• See how telemetry can establish a valuable automated feedback loop
• Find data models you can build on, and evaluate models with similar functionality
• Understand models, metadata, and tools from several viewpoints: architect, operator, module author, and application developer
• Walk through a complete automation journey: business case, service model, service implementation, device integration, and operation
• Leverage the authors’ experience to design successful YANG models and avoid pitfalls
  

Table of Contents:
Introduction xxii
1 The Network Management World Must Change: Why Should You Care? 2
    Introduction 2
    The Industry Has Changed: What Are the Trends? 6
    Existing Network Management Practices and Related Limitations 24
    Data Modeling Is Key for Automation 39
    Interview with the Experts 48
    Summary 52
    References in This Chapter 53
    Endnotes 53
2 Data Model—Driven Management 56
    The Beginning: A New Set of Requirements 56
    Network Management Is Dead, Long Live Network Management 59
    YANG: The Data Modeling Language 61
    The Management Architecture 69
    Data Model—Driven Management Components 70
    The Encoding (Protocol Binding and Serialization) 74
    The Server Architecture: Datastore 77
    The Protocols 78
    The Programming Language 85
    Telemetry 86
    The Bigger Picture: Using NETCONF to Manage a Network 86
    Interview with the Experts 91
    Summary 93
    References in This Chapter 93
    Endnotes 94
3 YANG Explained 96
    Introduction 96
    Describe Your World of Data 96
    Describing Possible Events 113
    Separating Configuration from Operational Data 117
    Constraints Keep Things Meaningful 122
    Augmenting, Extending, and Possibly Deviating 142
    Network Management Datastore Architecture (NMDA) 149
    Interview with the Expert 154
    Summary 156
    References in This Chapter 157
4 NETCONF, RESTCONF, and gNMI Explained 158
    Introduction 158
    NETCONF 158
    RESTCONF 190
    OpenConfig and gNMI 214
    Interview with the Expert 225
    Summary 227
    References in This Chapter 227
5 Telemetry Explained 230
    Introduction 230
    Data Model—Driven Telemetry 230
    Moving Away from SNMP to Telemetry 232
    Telemetry Use Cases 235
    Telemetry Components 236
    Telemetry Standard Mechanisms 242
    Interview with the Experts 249
    Summary 252
    References in This Chapter 253
    Endnotes 253
6 YANG Data Modeling Developments in the Industry 256
    Introduction 256
    The Beginning: The IETF 256
    Embracing YANG Throughout the Industry 263
    The OpenConfig YANG Model 268
    Industry Coordination Is Required 270
    Interoperability Testing 272
    Implementing More Than One YANG Model for a Specific Functionality 274
    Interview with the Expert 275
    Summary 278
    References in This Chapter 279
    Endnotes 279
7 Automation Is as Good as the Data Models, Their Related
    Metadata, and the Tools: For the Network Architect and Operator 282
    Introduction 282
    Getting to Know the Structure of a YANG Module 283
    Finding the Right Modules Using the YANG Catalog 287
    Interacting with Devices 299
    Interview with the Experts 331
    Summary 335
    Endnotes 335
8 Automation Is as Good as the Data Models,
    Their Related Metadata, and the Tools: For the Module Author 336
    Introduction 336
    Designing Modules 336
    Understanding Your Module’s Impact 349
    Interview with the Expert 350
    Summary 352
    Endnotes 352
9 Automation Is as Good as the Data Models, Their Related Metadata, and the Tools: For the Application Developer 354
    Introduction 354
    Working with YANG Modules 355
    Interacting with the Network 366
    Making YANG Language Native 373
    Interview with the Expert 380
    Summary 381
    Endnotes 382
10 Using NETCONF and YANG 384
    Introduction 384
    So the Story Goes 385
    Top-Down Service Model 386
    Bottom-Up Device Templates 392
    Service Logic Connecting the Dots 394
    Setting Up NETCONF on a Device 398
    Discovering What’s on a Device 400
    Managing Services 405
    Manager Synchronization with Devices 413
    Network-Wide Transactions 417
    Interview with the Experts 425
    Summary 428
11 YANG Model Design 430
    Introduction 430
    Modeling Strategy 430
    YANG Modeling Tips 433
    Common YANG Mistakes 443
    Backward Compatibility 457
    Interview with the Experts 460
    Summary 462
    References in This Chapter 463
9780135180396, TOC, 4/4/19