PDF of this tutorialTMN Building Blocks
The TMN is represented by several building blocks that provide an overall embodiment of the management issues and functions of TMN. Figure 2 illustrates the building blocks in TMN.
Figure 2. TMN building blocks
Table 1 lists and describes each TMN component and the function that it performs. In some cases, functions may be performed within other system components. The mediation device (MD), for instance, may also provide some of the functions defined as operations systems (OSs), Q adapters (QAs), and workstations (WSs). In addition, the OS may also provide some of the MDs, QAs, and WSs.
| System Component | Description |
| OS | performs operations system functions, including operations monitoring and controlling telecommunications-management functions; the OS can also provide some of the mediation, q-adaption, and WS functions. |
| MD | performs mediation between local TMN interfaces and the OS information model; mediation function may be needed to ensure that the information, scope, and functionality are presented in the exact way that the OS expects. Mediation functions can be implemented across hierarchies of cascaded MDs. |
| QA | The QA enables the TMN to manage NEs that have non–TMN interfaces. The QA translates between TMN and non–TMN interfaces. A TL1 Q-adapter, for example, translates between a TL1 ASCII message-based protocol and the CMIP, the TMN interface protocol; likewise, simple network management protocol (SNMP) Q-adapter translates between SNMP and CMIP. |
| NE | In the scope of TMN, an NE contains manageable information that is monitored and controlled by an OS. In order to be managed within the scope of TMN, an NE must have a standard TMN interface. If an NE does not have a standard interface, the NE can still be managed via a Q-adapter. The NE provides the OS with a representation of its manageable information and functionality (i.e., the MIB). Note that the NE contains NE functionality—that is, the functions required in order to be managed by an OS. As a building block, the actual NE can also contain its own OS function, as well as QA function, MD function, etc. |
| WS | The WS performs workstation functions. WSs translate information between TMN format and a displayable format for the user. |
| data communication network (DCN) | The DCN is the communication network within a TMN. The DCN represents OSI layers 1 to 3. |
Table 1. Functional Components
Distribution Of TMN Management Functions
One type of management activity can be broken into a series of nested functional domains, each of which can exist in the same or separate logical layers. Each functional domain is under the control of an OS. Because management can be divided among OSs within the TMN environment, distributed management tasks can occur. One user transaction might encompass several management tasks. The logical layers enable that transaction to be processed across several OSs in a tree-like but nested hierarchy. Note that functional domains are nested within one another, and OS functional blocks communicate with each other. The layers may be distributed to recursive subordinate OSs within one TMN environment.
OSI Functionality in TMN
Stack Support
TMN defines a message communication function (MCF). All building blocks with physical interfaces need to have an MCF. An MCF provides the protocol layers necessary to connect a block to a DCN (i.e., layers 4 to 7). An MCF can provide all seven OSI layers, and it can provide protocol convergence functions for interfaces that use some other layer configurations (e.g., a short stack).
Manager and Agent Roles
TMN function blocks can act in the role of a manager and/or agent. The manager/agent concepts are the same as those used for CMIP and OSI management. In other words, a manager process issues directives and receives notifications, and an agent process carries out directives, sends responses, and emits events and alarms. As shown below, a building block may be viewed as a manager to one peer, even though it is viewed as an agent to another peer.
