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66 to the OS upon detection of a serious fault in the network, but it also controls diagnostic and test routines: - Alarm Surveillance The SDH NEs have the capability to send alarm reports to the OS upon detection of a failure, and to store the alarms in an event log - Fault Localisation and Testing The SDH NEs can be ordered to perform loopbacks, error injection, self-diagnostics, etc. Performance Management (PM) Performance management deals with the functions necessary for an NE to collect, store, threshold, and report performance data associated with its monitored PDH and SDH trail terminations. All applicationspecific and optional parameters, as specified in CCITT Rec. G.784, are supported. - PM Data Attribute Setting Basic PM data attributes, such as threshold values, can be defined - PM Data Reporting The SDH NEs can send PM data reports to an OS, either when a defined threshold is exceeded (degraded or unacceptable performance level) or in accordance with predefined schedules - PM Data Logging PM data can be stored in logs within the NEs and fetched by the OS when demanded. Security Management (SM) Security management functions deal with user access control to protect the network against unauthorised access to resources and services. - Login/Logout A local operator trying to access the NE is checked against a user identity and a password • User Categories A user category defines different levels of function access privileges that can be assigned to a user. The lowest privilege level is read access, and the highest level is the super-user category • Users New users can be defined and assigned a user identity, password and user category. Users can also be deleted. DCN Management DCN Management provides the functions necessary to control and configure the data communication resources which allow communication to take place within the SDH Management Network. - Network Node Configuration Each SDH NE can be configured as a data communication node in the OSI environment, which means that addresses, application entity titles and names used locally must be defined - Network Route Configuration Network routes in the OSI context can be defined by means of routing tables and route priorities. The Information Model Perspective Another, more formal way of describing the operation and control functionality is in terms of an Information Model (IM). An IM is an object-oriented description, independent of the actual physical realisation of the Network Element resources and how these are managed. The Information Model consists of a collection of object classes, e.g. equipment, software, trail termination point, SDH Fig.1 Model of Duplex Cross-connection Ptr CTP Bi Pointer Connection Termination Point Bidirectional ERICSSON REVIEW No. 3, 1992
67 switch fabric. The characteristics of an object class are specified in terms of - read/write attribute values in objects, e.g. values of configuration parameters and relations to other objects, represented as lines between objects in Fig. 1 2 3 - create/delete operations of objects - actions that can be performed on the object - notifications (i.e. spontaneous messages) sent from the object. In an executing system, manageable resources are represented as instances of these object classes. The collection of instantiated objects is referred to as the Management Information Base (MIB). 2 There are two types of object in the MIB: Managed Objects and Support Objects. A Managed Object (MO) represents a physical or logical resource in the Network Element. A Support Object (SO) represents a log or an alarm filter, for example. The link between the TMN management functions and the IM is the implementation of each management function as one or more operations, actions or notifications in the objects that build up the MIB. A Network Element has what is called a TMN Agent, which can be seen as a process (function) acting on behalf of the managing system(s), relaying messages in both directions, Fig. 2. A generic Information Model is essential for the generation of management standards concerning configuration, fault, performance and security management functions. A common network model, identifying the generic resources in the network - in this case the Transport Network- and their associated attribute types, events, actions and behaviour, provides a basis on which to explain the interrelationships between these resources and the network management system. Without this common view, a multi-vendortelecommunication network will not be achieved. The Information Model provided by Ericsson and describing the SDH NE complies with the information model developed by CCITT's SG XV SDH Model (G.774), 6 and with the SG IV Generic Network Information Model (M.3100). 5 In general, the configuration management part is derived from G.774, while the fault management and performance management parts are derived from M.3100 and Q.821. By and large, SG IV follows the CCITT X.700 series of recommendations. The SDH Information Model is a subset of the ETNA Information Model common to all Ericsson transport network elements connected to the FMAS, including PDH equipment and AXD I/O NEs. The Data Communication Perspective As well as providing telecommunications services, the SDH NEs also provide powerful data communications and network layer routing functions. The TMN function block that performs these functions is called the Message Communication Function (MCF). The MCF is based on the OSI reference model, which makes it possible for an SDH NE to work as a data communication node in an open network architecture. 7 Each of Ericsson's SDH NEs can be equipped with a Q-interface and provide for Embedded Control Channel (ECC) access, which means that each NE can be connected to any Operations System that conforms to OSI and TMN standards, without the need for additional Mediation Devices or Q-adapters. The MCF performs network layer routing functions between the Q-interface and any Fig. 2 Interworking between Manager, Agent and Managed Objects ERICSSON REVIEW No. 3, 1992
Page 1: ERICSSON REVIEW 3 1992 An Introduct
Page 4 and 5: An Introduction to the Ericsson Tra
Page 6 and 7: 60 Fig. 3 AXD 155 system integratio
Page 8 and 9: Control and Operation of SDH Networ
Page 10 and 11: 64 These functions and a number of
Page 14 and 15: 68 BOX 3 The SDH NE MANAGEMENT ORGA
Page 16 and 17: Fig. 4 Control System Architecture
Page 18 and 19: 72 Fig. 6 Software Architecture CSA
Page 20 and 21: 74 Functional requirements Certain
Page 22 and 23: 76 Fig 10 SMUX Control System Hardw
Page 24 and 25: AXD 4/1, a Digital Cross-Connect Sy
Page 26 and 27: 80 Fig. 2 AXD 4/1, System Architect
Page 28 and 29: 82 Fig. 3 Time Space Switch structu
Page 30 and 31: 84 Fig. 4 AXD 4/1 Devices Devices o
Page 32 and 33: 86 The control signals, which come
Page 34: 88 Fig. 8 Protection Switch Unit st

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