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Principal Sponsors:
 | Embedded Telecommunications Management Network (TMN) Solutions |
4. TMN Agents Use Object-Oriented Technology
Object orientation is a technique that allows two objects to communicate with each other without knowing the internal processes of the other object. It also allows programs to operate on objects without knowing the internal operations of the object. This is a good way to do network management because it makes interoperability easy. As long as the operations conform to standards, the object itself can be proprietary, and it can interoperate with another object. Object orientation also allows for salability and reuse, making integration with new technologies easy.
It is necessary to understand the following concepts in order to talk about object-oriented embedded TMN agents:
- An object is a software package that contains a collection of related methods (actions that can be performed) and variables (data that can change over time).
- A class is a template that defines the methods and variables to be included in a particular type of object.
- Instances are objects that belong to a class but contain specific values for the variables.
So, in essence, an object is an instance of a particular class, where the method of the object is specified by its class and the value of the object is defined by its instance.
In TMN agent technology, agent development is based on a containment tree (see Figure 4), which is a database of named object instances. It uses hierarchical naming, so objects are contained within objects. The containment tree actually holds the object instances that occur on the real resource. This hierarchical control allows for scoping and filtering functionality. Scoping lets multiple objects be operated on at once. Objects within the scope can be filtered based on their attribute values. This makes management much more precise and, as a result, saves bandwidth.
On the manager side, however, a management information base (MIB) is used (see Figure 5). An MIB is an abstract representation of real resources on the network. It provides the manager with an outline of how real resources are going to look and act on each NE.
The difference between a MIB and a containment tree is important to understand. For example, specific attributes can be defined for a country. It can be said that it has cities, capitals, and states. These terms can be defined specifically. For example, the definition of a city is "an inhabited place of greater size, population, or importance than a town or village." All of this information would be contained in the MIB. Now think of a specific country, such as the United States. With this specific country in mind, one can list specific cities, capitals, and states. This is the containment tree, or the set of real things, as defined in the MIB.
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