 Management functions ment Network (TMN). Work started on TMN in 1985 and it has since been developed by ANSI, CCITT and ETSI. ANSI approached Layer 7 within the OSI model has the Systems Management Appli- this on a bottom up basis, first determining what management data, cation Entity (SMAE), which contains the System Management and in what format, the network elements can provide to the oper- Application Service Element (SMASE). An SMASE is associated ator, before specifying management requirements. CCITT and with each manager and its agent, and for communication the ETSI, on the other hand, started by first defining the network SMASE uses the services of CMIS which are carried to the remote management functions which would be needed to control a telecom- system via CMIP. This manipulates the MIB using low level oper- munications network, and then working downwards to define the ations such as SET and GET. data and format needed to implement these functions. All three SMASE encompasses a set of System Management Functions groups are co-ordinating their activities closely. The principles for (SMF) which define the mechanism by which certain tasks can be a Telecommunications Management Network are described in undertaken on the managed objects. Examples of these are as CCITT Recommendation M.30. follows: The basic concept behind a TMN is to provide an organised network structure, to achieve the interconnection between various Object Management, covering the mechanism used to create, types of Operations Systems (OS) and telecommunications equip- delete and manage the attributes within the objects. ment using an agreed architecture and with standardised interfaces. 2. State Management, covering the object states, and the mechan- Figure 16.17 shows the relationship between the TMN and a tele- isms which may be used to change them. communications network. The telecommunications network can 3. Relationship management, covering the principles of contain- consist of both digital and analogue telecommunications equip- me