OBJECT ORIENTED MODELLING AND DEVELOPMENT OF OSI NETWORK MANAGEMENT

Abstract

Many standard documents of Open System Interconnection (OSI) network management have reached international standards and have been widely accepted by telecommunication and computer industries. The OSI Management Reference Model document provides the basic framework for network management within the OSI environment. The model uses object oriented (OO) methodology in its specifications, but does not compel that an OO implementation. The primary objective of this project is to design and develop an object-oriented model for OSI network management. It encompasses an OO design and implementation of the network management communication infrastructure based on open industry standard application programming interfaces (APIs). The APIs used are X/Open OSI-Abstract-Data Manipulation (XOM) and X/Open Management Protocol (XMP). OSI applications such as the Event and Log Manager and the modelling tools for OSI managed objects are developed to demonstrate the applicability and workability of the infrastructure and its APls. Network management belongs to the application layer of the seven-layer OSI Reference model. Unlike other layers, the application layer structure is comprised of many application service elements (ASEs) which work harmoniously among one another to provide protocols and services for multiple applications. The ASEs involved in OSI network management are ACSE, ROSE, SMASE and CMISE. These ASEs are analysed and modelled using OO techniques to conceptualise an overall framework for network management. Details of the analysis, design and architecture arc discussed in Chapter 3. The architecture achieves modularity through logical entity construction based on the well-documented protocol layering standards. The manner in which these entities arc structured is based on the Application Layer Structure (ALS). The interactions of the various entities are taken into consideration when designing the overall architecture so as to produce an efficient OO model. Consortiums and user groups were formed to encourage network interoperability and accelerate OSI development and its applications. They help to harmonise on implementation agreements such as application programming interfaces (APls). The management protocol API known as XMP API has been standardised in X/Open consortium. This set or API is said to be language-independent, but a C language context is given. Implementation in other languages is possible but not given. In Chapter 4, an attempt is made to design and implement the XOM and XMP APIs using OO techniques and the C++ language. A C++ API interface is designed and implemented. The implementation provides a backward compatibility to the original C-language binding APls. With the communication infrastructure and its associated APIs integrated, the next step is to develop suitable OSI applications and tools to test its workability. This will help to demonstrate the effectiveness of adopting the OO architecture. In order to manage the OSI environment effectively, there is a need to control and store events. The controlling and logging mechanisms are documented in Systems Management Functions (SMFs) documents. In Chapter 5, the design and implementation of an OO model or the OSI Event and Log Manager is presented. The manager can filter and schedule the forwarding and logging of event reports based on its slate and control objects. This complex mechanism should serve as a good example of implementation. Ii will help to understand, test and use the intricacies of the OO architectural model and its APIs. The OO design also allows for a progressive modelling and implementation approach. Two OSI SMF functions, ERM and LCF, are analysed, modelled and implemented in an OO manner. The approach effectively maps the objects defined in GDMO format into the respective Event and Log Manager C++ classes. The modelling technique used is based on the Object Modelling Technique (OMT). All the designed classes are also defined using XOM objects so that they can be seamlessly integrated to the proposed infrastructure. Finally, the complete implementation is built on the communication infrastructure for accessing the CMISE services through the XOM and XMP APIs. OSI managed objects are designed and structured based on the complex and voluminous Structure of Management Information (SMI) standards. In SMI, there are nine templates defined to structure all the various OSI managed objects. As the number of defined managed objects increases, the complexity of managing these definitions becomes a chore. To overcome this situation, a browsing and modelling tool is needed. This tool can help to improve the productivity of managed object definers and librarians. This tool is known as GDMO tool. It is envisioned that the tool should consist of a class browser which can read and process GDMO compliant definitions, a modelling environment, which allows new definitions or existing definitions to be modelled or refined, and the necessary management information database. It should have an easy-to-use user interface, designed to reduce time and cost of creating, browsing and designing GDMO definitions. Besides providing the traditional views of the system such as cross referencing information and metrics, the tool can also provide management views such as inheritance, registration and containment trees. It also support queries and referencing on existing definitions which made searching easier and efficiently. In Chapter 6, the OO analysis and design of the tool is described. The OO technique adopted is the HP Fusion method which is different from the previous technique. The use of different OO techniques is to appreciate rather than to compare their effectiveness. Finally, the implementation is carried out using C++. For the implementation of all the software modules mentioned above, the Borland C++ v 1.0 C++ language is used. The flexibility of the language has greatly facilitated the effective implementation or the architecture and its data structures. Graphical user interfaces were used in areas where they can help to ease the complexity of information presentation and acquisition. The complete implementation is integrated to the OSI attack which had been previously implemented. The entire protocol suite is implemented on OS/2 v2.1 on IBM PCs or compatibles. Tests were carried out using two PCs running on the OSI LAN. The observed results conform to design specifications. The user interface development is carried out using an application framework package, zApp, which shortens the GUI development efforts tremendously. The aggregate source code amounted to a total of approximately 50,000 C++ lines of codes excluding headers and comments.