PDF of this tutorialIntroduction
You don't have to know anything about the telecommunications management network framework to take advantage of EMSs. Although the element management layer is a chief component of the five-level TMN pyramid, all carriers really have to know about EMSs is that they make the job of managing networks of multivendor elements a whole lot easier.
—Dan O'Shea, Supplements Editor
"Taming the Elements," Telephony, September 14, 1998
The TMN–FCAPS model of OSS tasks is a useful construct and is often referenced. It is, however, too abstract to use to understand the operational contribution and economic value of EMSs.
Service providers (SPs) think in terms of work (and the related cost and time) that must be invested to provide service to customers. A good example of this is a 1997 study by the TeleManagement Forum (formerly the Network Management Forum [NMF]). This study, based on interviews with service providers, identified a number of high-level processes and supporting subprocesses that should be accomplished by each layer of the TMN architecture.
The TeleManagement Forum–defined, high-level processes for which the EML 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 EMSs make the link to the NML for tasks such as integrated fault management 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 EMSs 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 (SMSs); 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
EMSs with open, standard, northbound interfaces provide the solid foundation required for service providers to deploy the TeleManagement Forum–defined, high-level processes by applications at the TMN framework network, service, and BMLs. EMSs also offer significant value via cost- and time-reducing tasks provided in addition to enabling cost-effective development of the TeleManagement Forum high-level processes.
This tutorial supports and represents the value contribution of the EMS with a four-function model. This model incorporates all tasks performed by an EMS and includes the following:
- Function 1: service provisioning
- Function 2: service assurance
- Function 3: EMS and NE operations support
- Function 4: automation enabler
Topics 5 through 8 describe typical tasks that legitimately belong in the four-function domain of an EMS. These tasks represent significant potential cost savings and revenue generation for service providers. EMSs are now valuable components of the network in their own right and not mere extensions of the NE craft interface as EMSs have often been perceived in the past. Not all EMSs will perform all of these tasks; some will perform these tasks and more; and some will perform unique tasks that target the requirements of a particular NE.
This four-function model is meant to serve as a useful guide to service providers for evaluating the array of choices for managing the NEs in their own unique operating and business context. A user working through the EMS graphical user interface (GUI) may accomplish some or all of the tasks within each of the EMS four-function model. Whether or not a specific function is accomplished via the EMS GUI depends upon whether or not the task is subsumed in an application performed at a higher level.
