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Principal Sponsors:
 | Embedded Telecommunications Management Network (TMN) Solutions |
5. Implementing a TMN Agent
There are three basic steps to developing a TMN agent application: developing the information model, creating the actual software code, and testing the agent application.
To develop the information model, it is necessary to use a specification language. The specification language used in TMN to define managed objects is called guidelines for the definition of managed objects (GDMO). GDMO uses abstract syntax notation one (ASN.1) to define data elements in an independent manner for exchange over a communications network.
Both GDMO and ASN.1 are difficult to learn because the syntax is very complicated. But various types of tools exist to help develop the GDMO. Some tools use graphics to help develop relationships between objects in the information model and then automatically generate the GDMO information model so that it isn't necessary to write any GDMO oneself. Tools also may also allow for the development of the main structure of the information model using standard managed object (MO) classes, and then one can augment them with particular characteristics, constraints, inheritance relationships, and naming trees that are specific to one's application. Alternatively, one can create the GDMO by hand.
After creating the GDMO model, it is necessary to develop the C++ code for the agent application. Each application that is built must be customized for the specific RTOS on which it will run. Usually this necessitates porting the application to the appropriate RTOS or writing code specifically for the RTOS. It also is necessary to write the code that will associate the GDMO managed objects in the model to the real resources of a device. Finally, it is important to test the agent to ensure that it runs properly on the network. To do this, it is necessary to write a program that will mimic a manager application.
To add to the agent application after it is developed, it is necessary to add to the MIB using GDMO and to repeat all of the steps again. As a result, tool kits that offer iterative development are extremely useful.
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