Network Operators and Service Providers use the terms Element Manager or Element Management System or EMS or Domain Manager, for the management solutions delivered by equipment manufacturers to enable network management of their devices.

Not all EMSs are equal, and users have preferences that are the result of using multiple EMS solutions and identifying the strengths and weaknesses of each one. Users refer to the FCAPS model (Fault Management, Configuration Management, Accounting, Performance Management, Security) to describe and categorize the features and functions supported by the EMS.

This article provides a list and description of the FCAPS features that should be provided by an EMS or Domain Manager, to allow the Network Operator and Service Provider to efficiently monitor and manage a network. It also provides the definitions of the EMS, NMS and Domain Manager terms as a lot of people get confused with these three terms.

What is an EMS?

An Element Management system (EMS) manages one or more of a specific type of telecommunications network elements (NE). It also manages functions and capabilities within each NE but does not manage the traffic between different NEs in the network. According to Wikipedia:

Element Management is concerned with managing network elements on the network element management layer (NEL) of the TMN (Telecommunications Management Network).

A detailed description of the TMN model can be found in the following article: What is the TMN model?

What is a  Domain Manager?

Networks are complex things with a wide range of technologies and equipment types, both new and old. So, the Network Operators require management tools to offer everything from basic administration to automated software management, intelligent fault management and complex multi-layer topology management.

The answer of the Equipment Manufacturers to this requirement, was the development of Domain Managers that gradually replace the Element Managers of the past.

Domain Managers are capable to manage all technologies and equipment types of a domain.

But wait, what is a “domain”? A Domain can be technology-specific e.g. all Point to Point Wireless links, or manufacturer-specific, e.g. all equipment delivered by the X manufacturer. The Domain Manager concept was defined by TeleManagement Forum in it’s TAM (Telecom Application Map) spec.


The FCAPS features that really matter

Now that I have EMS and Domain Manager terms covered, lets focus on the functions and features of the EMS and Domain Manager that are important :

[dropcap]F[/fusion_dropcap]ault management is about collecting alarms, maintaining accurate and current lists of alarms, visualizing alarms and network state. A bullet list for the important features would include:

  • Real-time events & alarms
  • Historical events & alarms
  • Active alarms
  • Historical alarms
[dropcap]C[/fusion_dropcap]onfiguration management is all about configuring the managed resources, (network equipment or services), auditing the network and discovering what’s in it, synchronizing the management information in the network with management information in management applications,  backing up network configuration and restoring it in case of failures, managing software images running on network equipment. A bullet list for the important features would include:

  • Discovery
  • Topology
  • Configuration
  • Service provisioning
  • Current hardware & software inventory
  • Configuration backup / restore
  • Software upgrade
[dropcap]P[/fusion_dropcap]erformance management is about performance metrics and performance analysis. A bullet list for the important features would include:

  • Current performance monitoring for troubleshooting.
  • Presentation with graphs and charts updated in real-time.
[dropcap]S[/fusion_dropcap]ecurity management is about security of Management (Systems & Network) and management of security (of devices). A bullet list for the important features would include:

  • Secure authentication (password)
  • Roles, privileges

In the following paragraphs, I will focus more on the functions that are key to the network operators.

Network and Devices Discovery

Discovery is a key Configuration Management feature. The Domain Manager allows users to carry out a deep discovery of their network, in order to discover not only all managed Network Elements (NEs), but also their “contained” objects, inclusive of cards, ports, connections, etc.

Discovery can be performed:

  • Manually: One-by-one addition of domains, Network Element (NEs) and topological links.
  • Massive: This is typically done by import of a file containing the configuration of the whole network. This feature is very useful, especially when upgrading the network
  • Scheduled: This is the automatic discovery of the pre-planned network based on user-defined schedules. In this case there is no need for prior NOC notification in case of network rollout (e.g. installation of a new NE).

Network and Devices Topology

Topology is  very useful for large, distributed networks

[. Topology allows users to monitor the operational status of their network, in real-time, through an integrated graphical mapview.

Network Topology is supported through configurable background maps – vectored or images – where domains and
managed elements are represented graphically. Advanced drill-in /out and zoom-in /out functions, as well as photo-realistic interactive equipment views, enhance the real-time alarm and operational status monitoring and are strong points of some of the monitoring tools available.
The topology features typically include:

  • On-map graphical alarm & operational status monitoring with real-time indications, which are color-coded – status is propagated to domains and sub-networks.
  • Ability to execute actions directly (configuration, performance, faults, etc.).
  • Photorealistic equipment views.

Configuration Management

Configuration prepares and sets the network devices for operation. Configuration Management provides centralized device and network configuration, also offering:

  • Initial configuration of the network elements and of their components.
  • Monitoring and synchronization of network configuration parameters.
  • Massive configuration with templates.
  • Configuration of advanced parameters, such as VLANs, QoS, radio protection, etc.
  • Configuration backup and restore.

Software Management

Software Management simplifies Network Maintenance. Configuration also includes the capability for Software Management.

Software Management enables remote and centralized software updates for the managed elements in order to keep the
network elements up-to-date, or to add new management features.

Fault Management

Fault Management detects, isolates and resolves problems in order to keep the supervised network running
optimally, provide a measure of fault tolerance and avoid any possibility for downtime.
Users can monitor alarms in real-time, while active and historical alarms are stored in the relational database. Alarms are presented with additional views that provide extensive filtering and exporting capabilities.
The Fault Management features include:

  • Alarms collection in real time and synchronization.
  • Trap anti-flood protection.
  • Availability monitoring through management heartbeat.
  • Alarms reduction through classification (severities), filtering, maintenance mode, top level graphical view.
  • Alarms troubleshooting through historical alarms, context-sensitive menus and photo-realistic equipment views.
  • Alarm notifications through email and SMS.


Performance Management

The Domain Manager constitutes a means of measuring the quality of several operational parameters in real time.
Performance Management ensures that the supervised network operates as expected and that the available network resources are efficiently allocated.
Indicatively, the parameters that can be monitored include:

  • Radio parameters (RSL, RSSI, CNR, etc.).
  • G.826
  • RMON
  • Ethernet parameters


Test Management

Test Management localizes faults and detects possible trouble spots within the managed network.
The testing capabilities, which include BER tests, setting of loopbacks, etc., are provided for all managed elements.
The Domain Manager or the Element Manager manages test execution and progress, while test results are presented in real-time.


I know this is a long article, but it barely touches the surface of the FCAPS when it is actually implemented in network management systems. Do you think that a feature of function is missing? Talk to me!

“With the Domain Manager, Network Operation Centers are able to remotely configure, provision and monitor Network Elements, and ensure the timely rollout of networks and their reliable operation. “
NOC manager, Service Provider