Frame Relay - for Faster and More Efficient Data Communications ...

The Managed Objects and their propertiesare contained in Network Information Models.The Generic Network InformationModel defines Managed Objects that arecommon to many different technologies.Specific Network Information Models havebeen developed - or are being developed- for SDH, PDH and ATM networks.Fig. 18Entity Relationship diagram derived from theTransport Functions in Fig. 6TTPCTPn>lTrail Termination Point MOConnection Termination Point MOAdaptation including multiplexingNamingConnectivity pointerManaged ObjectFig. 19Identification of termination point Managed ObjectsNumbers in parentheses are related to PDH functionsin Fig. 13BID Bidirectionalstance and may possess multiple attributetypes and associated values. An objectclass may be a subclass from another objectclass. A subclass inherits attributetypes and behaviours of its superclass, inaddition to possessing its own specific attributesand properties. Each object instanceis identified by a unique name.Such a unique name is composed hierarchicallyand the most common way of organisinga naming hierarchy is through acontainment relationship. The relationshipbetween Managed Object classes can beexpressed with Entity-Relationship diagrams.Inheritance hierarchy diagramsshow the subclassing of Managed Objects.3Generic and specific Managed Objects arelisted in a standardised form in ManagementInformation Bases (MIB). The processof defining "all" new Managed Objectsfor the existing telecommunicationnetworks will take many years, and newManaged Objects have to be foreseen asnew technologies are introduced.Use of FragmentsA number of views, referred to as Fragments,are used as a practical means ofdividing the Information Model into well definedparts. These Fragments can be appliedto modelling - according to the relevantpurpose - more or less independentlyof each other. A Fragment can be illustratedby means of Entity-Relationship diagrams.The following Fragments are derived fromFunctional Models:- Network Fragment- Managed Element Fragment- Termination Point Fragment- Transmission Fragment- Cross-connection Fragment.This article focuses on the TerminationPoint and Cross-connection Fragments.These Fragments assemble the ManagedObjects required for the management ofcross connects, muldexes and linesystems, i.e the main components of transmissionnetworks.The Managed Objects for the three otherFragments will be described on a technology-independentbasis in a future article.Information ModelThe functional modelling, which identifiesManageable Resources, provides the basisfor the information modelling leading toManaged Objects. The various InformationModels are introduced with referenceto the relevant Functional Models.ERICSSON REVIEW No. 1-2, 1992