All About EMS

An element management system (EMS) manages one or more of a specific type of telecommunications network element (NE). Typically, the EMS manages the functions and capabilities within each NE but does not manage the traffic between different NEs in the network. To support management of the traffic between itself and other NEs, the EMS communicates upward to higher-level network management systems (NMS) as described in the telecommunications management network (TMN) layered model. The EMS provides the foundation to implement TMN–layered operations support system (OSS) architectures that enable service providers to meet customer needs for rapid deployment of new services, as well as meeting stringent quality of service (QoS) requirements.

As recommended by ITU-T, the Element Management System's key functions are divided into five key areas - Fault, Configuration, Accounting, Performance and Security (FCAPS). Portions of each of the FCAPS functionality fit into the TMN models. The following grid shows a subset of the functionality prescribed by ITU-T and Telcordia for each of the key areas.

FCAPS functionality grid Fault Configuration Accounting Performance Security Alarm handling Auto Discovery Service Usage Performance Monitoring Prevention Alarm correlation Network provisioning Service level agreements Report Generation Authentication Alarm forwarding Auto back up and recovery Billing Data Collection and Correlation System Access Control Filtering and Filter management Service Activation - - Detection Log management Software upgrade to devices - - Intrusion Recovery Threshold based reporting Inventory management - - Containment and Recovery

Below Diagram shows the role of EMS in 5-layer TMN Architecture:

EMS must provide the base data and operations are the following: 

• Service provisioning
• Network development and planning
• Network inventory management
• Network provisioning
• Service assurance
• Network maintenance and restoration
• Network monitoring and control

It is important to understand that EMS's make the link to the NML for tasks such as integrated faultmanagement and flow-through provisioning. The EMS also often provides planning and analysis data directly to the higher-level SML and BML applications via bulk-data-transfer-protocol interfaces. The NML basically has three primary functions:

• Integrated fault management and causal analysis of multivendor and multitechnology networks
• Integrated, single screen, end-to-end service provisioning of multivendor and multitechnology networks
• Integration layer between the EML and the SML; this role is to bring together information from the EMS's that support it, and then integrate, correlate, and in many cases summarize that information, so as to pass on relevant information to service management systems (SMS's); that information generally relates to the characteristics of the network technologies involved but should describe an end-to-end view that is consistent across the (multiple) technologies that are usually required to support a specific  customer service; in the reverse direction, the NML receives information from the SML, processes it, and passes on relevant commands and data to the appropriate EMS; the EMS then sends specific commands to the NE.EMS's with open, standard, northbound interfaces provide the solid foundation required for service providers.

An EMS's architecture should meet some of the following basic requirements:

• It should provide the correct level of management functionality appropriate to the device and to the management environment.
• It should be scalable to grow with the requirements and complexity of the network.
• It should be distributable in order to support such scalability and to provide a level of high availability.
• Database technology is a critical part of any credible EMS strategy.                                 

Below diagram shows the basic architecture of a EMS:

 

                                                                                                                                                                         

                                                                                                 Source: ems-info.synthasite.com

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