nsport layer standards elements). These may be physical elements, such as exchanges, request (A) to CMISE to set up a connection to the Operations transmission equipment, cable, cross-connects, or it may consist of System. The CMISE primitive used is 'M-INITIALISE request. abstract elements, such as maintenance entities and support entities. CMISE forwards this request to ACSE using 'A-ASSOCIATE re- The interchange of information within the TMN uses the OSI quest' as at (B). ACSE passes this request on and it goes down the seven layer model and the services within these layers. For example OSI stack, is transmitted to the Operations System, and up its stack Figure 16.18 illustrates the flow of information when an alarm is until it reaches the application layer at (D) with the primitive 'M- raised by a network element and sent to its Operations System. The INITIALISE request.' The Operations System acknowledges this alarm is sensed by the relevant TMN application. This sends a request via (E) until it arrives at the originating network element at 16/16 Network management OPERATIONS OPERATIONS OPERATIONS SYSTEM SYSTEM SYSTEM DATA COMMUNICATIONS NETWORK TRANSMISSION TRANSMISSION EXCHANGE EXCHANGE EXCHANGE SYSTEM SYSTEM TELECOMMUNICATION NETWORK Figure 16.17 Relationship between the TMN and a telecommunication network (F) as 'M-INITIALISE confirm'. Alarm information is now sent by 16.8.1 The TMN architecture the network element as 'M-EVENT REPORT request' at (G) to CMISE, which calls ROSE at (H) with 'RO-INVOKE request'. The TMN architecture consists of three elements: functional archi- Eventually the alarm message reaches the Operations System as tecture; information architecture; and physical architecture. 'M-EVENT-REPORT indication' at (I). The functional architecture may be considered to be the building blocks which allow complex systems to be built. NETWORK ELEMENT OPERATIONS SYSTEM TMN APPLICATION TMN APPLICATION CMISE CMISE Figure 16.18 Interchange of information between a Network Element and Operations System