NRM Network Resource Model

The Network Resource Model (NRM) is a model that provides a way to represent and manage the network resources in a telecommunications network. The NRM is an important component of the Telecommunications Management Network (TMN) architecture, which provides a framework for managing the various components of a telecommunications network.

The NRM provides a way to represent the network resources in a hierarchical structure, where each level of the hierarchy represents a different level of abstraction of the network resources. The lowest level of the hierarchy represents the physical resources, such as the cables, switches, and routers that make up the network. The higher levels of the hierarchy represent the logical resources that are built on top of the physical resources, such as the virtual circuits, logical links, and connections that make up the network.

The NRM is designed to be vendor-neutral, which means that it can be used with different types of network equipment from different vendors. This is important because most telecommunications networks are composed of equipment from multiple vendors, and the NRM provides a way to manage all of these resources in a consistent way.

The NRM is also designed to be extensible, which means that it can be adapted to support new types of network resources as they are developed. This is important because telecommunications networks are constantly evolving, and new types of network resources are being developed all the time.

The NRM is divided into two main parts: the information model and the communication model. The information model provides a way to represent the network resources, while the communication model provides a way to access and manipulate the network resources.

The Information Model

The information model is a conceptual model that provides a way to represent the network resources in a hierarchical structure. The model is composed of a set of object classes, each of which represents a different type of network resource. Each object class is composed of a set of attributes, which represent the properties of the object.

The object classes are organized into a hierarchical structure, where each level of the hierarchy represents a different level of abstraction of the network resources. The top level of the hierarchy is the network element level, which represents the physical devices that make up the network, such as routers, switches, and transmission equipment.

The network element level is composed of a set of object classes, each of which represents a different type of physical device. For example, there may be object classes for routers, switches, and transmission equipment. Each object class is composed of a set of attributes that describe the properties of the object. For example, a router object may have attributes that describe its IP address, its routing table, and its interface configuration.

The network element level is further divided into a set of subnetwork levels, which represent logical groupings of the physical devices. For example, there may be subnetworks for different geographic regions, different departments within a company, or different types of services provided by the network.

The subnetwork levels are also composed of a set of object classes, each of which represents a different type of logical grouping. For example, there may be object classes for virtual circuits, logical links, and connections. Each object class is composed of a set of attributes that describe the properties of the object. For example, a virtual circuit object may have attributes that describe its source and destination addresses, its bandwidth, and its quality of service parameters.

The Communication Model

The communication model provides a way to access and manipulate the network resources. The model is composed of a set of operations, each of which represents a different type of action that can be performed on the network resources. Each operation is associated with one or more object classes, and can be used to retrieve information about the objects or to modify the objects.

The communication model is divided into two main parts: the manager-to-agent communication model and the agent-to-agent communication model. The manager-to-agent communication model is used to communicate between the network management system (NMS) and the managed network elements. The agent-to-agent communication model is used to communicate between different network management systems.

In the manager-to-agent communication model, the NMS sends requests to the managed network elements to perform operations on the network resources. The requests are sent using a standardized protocol, such as the Simple Network Management Protocol (SNMP), and include the type of operation to be performed and any necessary parameters. The managed network elements receive the requests and perform the requested operations, and then send back a response to the NMS.

In the agent-to-agent communication model, the network management systems communicate with each other to exchange information and coordinate their activities. This is important in larger networks where there may be multiple management systems responsible for different parts of the network. The communication between the management systems is typically done using a standardized protocol, such as the Common Management Information Protocol (CMIP), and includes messages that contain information about the network resources and the operations to be performed.

Conclusion

The Network Resource Model (NRM) is a crucial component of the Telecommunications Management Network (TMN) architecture. It provides a way to represent and manage the network resources in a hierarchical structure, allowing for consistent and vendor-neutral management of the resources. The NRM's information model and communication model work together to provide a comprehensive framework for managing the network resources, allowing network administrators to efficiently monitor and control the telecommunications network. As telecommunications networks continue to evolve and new technologies emerge, the NRM can be extended to support these new network resources, ensuring its relevance and usefulness in the future.