Network Manager

Description

A Network Manager (NM) is a key component in the telecommunications management architecture, defined in 3GPP TS 21.905. It provides a package of end-user functions responsible for the management of a network. The NM typically operates at the network management layer (NML) of the Telecommunications Management Network (TMN) hierarchy, sitting above the Element Management layer (EML). It communicates with Element Managers (EMs) and, in some cases, directly with network elements (NEs) to perform management tasks. The NM is designed to manage multi-vendor and multi-technology networks through open and well-standardized interfaces, ensuring interoperability and flexibility.

The primary role of the NM is to provide a unified view of the network and to enable operators to manage network resources, services, and subscribers. It encompasses functions such as fault management, configuration management, accounting management, performance management, and security management (FCAPS). The NM collects data from EMs and NEs, processes it, and presents it to the operator through a graphical user interface or northbound interfaces. It also allows operators to configure network elements, deploy services, and monitor network health.

Architecturally, the NM interacts with EMs via standardized interfaces, such as the Itf-N interface defined by 3GPP. The Itf-N interface is based on the Integration Reference Point (IRP) concept, which defines a set of operations and notifications for management. The NM can also directly access NEs for certain management tasks, bypassing the EM, especially when the EM is not present or when direct access is more efficient. This flexibility is important in heterogeneous networks where some elements may not have a dedicated EM.

The NM is essential for network operations and maintenance. It enables centralized management, which reduces operational costs and complexity. It also supports automation and orchestration, which are critical in modern networks with network slicing and virtualization. In 5G, the NM role is often fulfilled by a Management and Orchestration (MANO) system or a Service Management and Orchestration (SMO) framework, which manages both physical and virtual network functions.

The definition of Network Manager has remained stable since Rel-4, indicating a consistent understanding of its role. However, the implementation has evolved with technology, from managing circuit-switched networks to packet-switched and now virtualized, software-defined networks. The NM continues to be a cornerstone of network management, ensuring that operators can efficiently manage increasingly complex networks.

Purpose & Motivation

The Network Manager exists to provide a centralized, end-to-end view and control of the network. In early telecommunications networks, management was often fragmented, with each vendor providing its own management system. This led to high operational costs and complexity, as operators had to integrate multiple management systems. The NM was created to abstract the underlying network elements and provide a unified management interface, regardless of vendor or technology. It solves the problem of multi-vendor interoperability by relying on standardized interfaces, such as those defined by 3GPP.

Historically, the NM concept emerged from the TMN model, which defined a hierarchy of management layers. The NM sits at the network management layer, responsible for managing the network as a whole, while EMs manage individual network elements. This separation of concerns allows for scalability and modularity. The NM addresses the limitations of element-specific management by providing a network-wide perspective, enabling operators to manage services that span multiple elements.

In modern networks, the NM is evolving to support network function virtualization (NFV) and software-defined networking (SDN). It must manage both physical and virtual resources, and it often integrates with orchestration systems to automate service deployment. The NM's role in ensuring end-to-end service quality and in enabling new business models, such as network slicing, is more critical than ever.