NETWORK MANAGEMENT STANDARDS
They are the OSI model, the Internet model, Telecommunications Management Network (TM\T), IEEE LANIWAN, and Web-based management. Several network management standards are in use today. Table 13.1 lists five standards and their salient points. The fifth standard, that is, web-based management is based on an emerging technology.
The Open System Interconnection (OSI) management standard is the standard adopted by the ISO. The OSI management protocol standard is Common Management Information Protocol (C:VIIP), and has built-in services, the Common Management Information Services (CMIS), that specify the basic services needed to perform the various functions. It is a set of specifications that addresses all seven layers of the OSI reference model. The specifications are object-oriented and hence the managed objects are based on object classes and inheritance rules. Besides specifying the management protocols, CMIP/CMIS also address the network management applications. Both LAN and WAN can be managed using CMIP/CMIS. Two of the major drawbacks of the OSI management standard are that it is complex and that the CMIP stack is layered. Until recently, memory of an ordinary desktop workstation was not sufficient to load a complete CMIP stack.
In contrast to CMIP, Simple Network Management Protocol (SNMP) is truly simple, as its name indicates. It started as an industry standard and has since become much like the standard specification for standards setting organizations. The Internet Engineering Task Force (IETF) is responsible for all Internet specifications including

network management. The managed objectives are defined as scalar objectives in SNMP. These were primarily intended to manage Internet components, but are now used to manage WAN and telecommunications systems. Probably because it is easy to implement, SNMP is the most widely implemented network management system today.
The Telecommunications Management Network (TMN) is designed to manage the telecommunications network and is oriented towards addressing telecommunications service providers. TMN is the standard of the International Telecommunication Union (ITU) and is based on OSI CMIP/CMIS specifications. TMN extends the concept of management beyond managing networks and network components; its specifications address service and business considerations.
The IEEE standards for LAN and MAN specifications are concerned only with OSI layers-1 (physical) and layer-2 (data link) and they are structured similar to OSI specification. Both OSI/CMIP and Internet/SNMP protocols use IEEE standards for the lower layers. The IEEE 802.x series of specifications defines the standards for the various physical media and data link protocols. IEEE 802.1 specifications present overview, architecture and management. The IEEE 802.2 standards specify the logical link control (LLC) layer. The LLC layer provides transparency of the various physical media and protocols to the network layer. The other specifications in the IEEE services are for specific media and protocols, for example, the 802.3 specifications for Ethernet LANs.
The last category in Table 3.1 is web-based management, which is based on web technology. It uses a web server for the management system, and web browsers for network management stations. Because this is an evolving technology, no standards exist at present. Two technologies are in vogue, Web-Based Enterprise Management (WBEM) and Java Management Extensions (JMX). A recently formed task force, Desktop Management Task Force (DMTF) is developing specifications for WBEM. The DMTF has chosen the Microsoft object-oriented management model, as the common information model. JMX is based on a special subset of Java applets developed by Sun Micro Systems that runs in the network components.
Network management is further complicated when the management system uses the new technology. The SNMP, being based on scalar technology and simple definition of managed objects, was widely favoured over CMIP. With the need for a total management of network, service, and business for telecommunications service providers, TMN. which uses CMIP, is being revived. CMIP, which was hard to implement because it required large memory and a better understanding of object­oriented technology, is now easier to implement. However, because of the numerous existing SNMP-based agents, SNMP is also being explored for implementing TMN. Both SNMP and CIIIP use polling methodology, which puts an additional load on the network. Besides. both require dedicated workstations for the network management system. With the new web-based management system, not only can object-oriented technology be implemented, but also the dedicated workstation constraint is removed by the uses of web browsers.
13.3 NETWORK MANAGEMENT MODEL
The OSI network model is an ISO standard and is vastly superior to all the models; it is structured and it addresses all the aspects of management. Figure shows an OSI network management architecture model that comprises four models, organizational model, information model, communication model, and functional model.

Although this classification of models is based on OSI architecture, and only some of the models are applicable to other architectures, it gives us a comprehensive picture of the different aspects of network management.
The organization model describes the components of a network management system, their functions, and their infrastructure. The organization model is defined in ISO 10040 OSI System Management Overview. It defines the terms object, agent, and manager. Network objects consist of network elements such as hosts, bridges, routers, and so on. They can be classified into managed and unmanaged objects or elements. The managed elements have a management process running in them, called an agent. The unmanaged elements do not have a management process running in them. The manager manages the managed element. There is a database in the manager, but not in the agent. The manager queries the agent and receives management data, processes it and stores it in its database. The agent can also send minimal set of alarm information to the manager, unsolicited.
The OSI information model deals with the structure and organization of management information. ISO 10165 specifies the structure of the management information (SMI) and the information database, Management Information Base (MIB). SMI describes how the management information is structured while MIB deals with the relationship and storage of management information.
The third model in OSI management is the communication model, which has three components: management application processes that function in the application layer, layer management between layers, and layer operations within the layers.
The functional model is the fourth component of OSI management. It deals with the user-oriented requirement of network management. OSI defines five functional application areas, namely, configuration, fault, performance, security and accounting. These are defined as system management functions in OSI.

  INFRASTRUCTURE FOR NETWORK MANAGEMENT
Network management includes the deployment, integration, and coordination of the hardware, software, and human elements to monitor, test, poll, configure, analyze, evaluate and control the network and element resources to meet the real-time, operational performance, and quality of service requirements at a reasonable cost. Because the network devices are distributed for the management to acquire the ability to monitor, test, poll, configure and control the hardware and software components in a network, the network administrator should be able to gather data (for example, for monitoring purposes) from a remote entity and be able to effect changes (for example, control) at that remote entity. A human analogy will prove useful here for understanding the infrastructure needed for network management.
Imagine that you are the head of a large organization that has branch offices around the world. It is your job to make sure that the pieces of your organization are operating smoothly. How would you do so? At a minimum, you will periodically gather data from your branch offices in the form of reports and various quantitative measures of activity, productivity, and budget. You will occasionally (but not always) be explicitly notified when there is a problem in one of the branch offices; the branch manager who wants to climb the corporate ladder (perhaps to get your job) may send you unsolicited.

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