10 YANG Data Modeling Explained
1. YANG Overview
YANG (Yet Another Next Generation) is a data modeling language used to model configuration data, state data, remote procedure calls, and notifications for network management protocols. It provides a standardized way to define the structure of data that can be managed over the network.
Example: Think of YANG as a blueprint for a house. Just as a blueprint defines the structure and layout of a house, YANG defines the structure and layout of network data.
2. Modules and Submodules
YANG models are organized into modules and submodules. A module is a collection of related definitions, including data nodes, RPCs, and notifications. Submodules are smaller units that can be included within a module to break down complex models into manageable parts.
Example: Consider a module as a book and submodules as chapters. Just as a book is divided into chapters for easier reading, a YANG module is divided into submodules for easier management.
3. Data Nodes
Data nodes are the building blocks of YANG models. They represent the data elements that can be configured or monitored. Data nodes can be containers, lists, leafs, and leaf-lists, each serving a specific purpose in defining the structure of the data.
Example: Think of data nodes as pieces of furniture in a room. Just as different pieces of furniture serve different purposes, different data nodes serve different purposes in defining network data.
4. Containers
Containers are data nodes that group related data nodes together. They provide a hierarchical structure to the data model, allowing for organized and logical representation of data. Containers can contain other containers, lists, leafs, and leaf-lists.
Example: Consider containers as rooms in a house. Just as rooms group related furniture together, containers group related data nodes together.
5. Lists
Lists are data nodes that represent a collection of similar data entries. Each entry in a list is identified by a unique key, allowing for efficient retrieval and manipulation of list entries. Lists are useful for modeling data that can have multiple instances.
Example: Think of lists as a bookshelf with multiple books. Just as each book on a shelf is identified by its title, each entry in a list is identified by a unique key.
6. Leafs and Leaf-Lists
Leafs are data nodes that represent simple data types, such as strings, integers, and booleans. Leaf-lists are similar to leafs but allow for multiple instances of the same data type. Leafs and leaf-lists are the terminal nodes in a YANG model.
Example: Consider leafs as individual items on a grocery list. Just as each item on a grocery list is a simple data type, each leaf in a YANG model is a simple data type.
7. RPCs (Remote Procedure Calls)
RPCs in YANG models define operations that can be performed on the network device. These operations can be invoked by network management systems to execute specific tasks, such as rebooting a device or retrieving diagnostic information.
Example: Think of RPCs as remote controls for a device. Just as a remote control can perform various operations on a device, RPCs can perform various operations on a network device.
8. Notifications
Notifications in YANG models define events that can be reported by the network device. These events can be triggered by changes in the device's state or configuration, allowing for real-time monitoring and alerting.
Example: Consider notifications as doorbells. Just as a doorbell notifies you when someone is at the door, notifications in YANG models notify you when an event occurs on a network device.
9. Schema Mounts
Schema mounts allow for the extension of YANG models into different namespaces. This enables the creation of modular and reusable data models that can be combined to form more complex models. Schema mounts provide flexibility in designing network data models.
Example: Think of schema mounts as LEGO blocks. Just as LEGO blocks can be combined to create different structures, schema mounts can be combined to create different data models.
10. YANG Tools and Editors
YANG tools and editors are software applications that help in creating, validating, and visualizing YANG models. These tools provide features such as syntax checking, model validation, and graphical representation of data models, making it easier to work with YANG.
Example: Consider YANG tools and editors as drafting tools for architects. Just as drafting tools help architects create blueprints, YANG tools and editors help network engineers create data models.