Contents

Network Management Application Functional Areas

In the early 1980s computer networks began to grow and be interconnected. As the size of these networks grew, they became harder to manage and maintain, thus the need for network management was realized. One of the oldest forms of network management is the use of the remote login to monitor or configure a network device; however, today more sophisticated network management tools are available. Network management is a requirement for anyone who wants to control and monitor their networks.

Management application functions have been categorized into five areas like fault, configuration, performance, security and accounting. These broad categories have been further subdivided into logical groups and each group defines atomic functions. The functions also vary depending on the abstraction level. These categories and examples of groups and individual functions along with the template for defining these functions are discussed in this chapter.

3.1 Basic Network Management Model:

The basic network management model (or architecture) is a starting point for understanding network management.

Four fundamental concepts of this model are:

Manager or Manager Role

Agent or Agent Role

Network Management Protocols

Management Information Base (MIB)

These concepts are used by network management protocols, including CMIP, SNMP, and SunNet Manager RPC protocols. The basic model and concepts are shown in the following figure.

Figure: Basic Network Management Model

3.1.1 Manager or Manager Role

In the network management model, a manager is a unit that:

Provides information to users

Issues requests to devices in a network. A request is used to ask a device to take some action. Typically the action requested is for a device to respond with specific information requested by the manager.

Receives responses to the requests

Receives unsolicited information from devices in the network concerning the status of the devices. These unsolicited reports are referred to as notifications and are frequently used to report problems, abnormalities, or changes in the agent environment.

Performing these activities is also referred to as acting in the manager role.

3.1.2 Agent or Agent Role

In the network management model, an agent is a unit that:

Is part of a device in the network that monitors and maintains status about that device

Can act upon and respond to requests from a manager

Can provide unsolicited information (or notifications) to a manager

Performing these activities is sometimes referred to as acting in the agent role.

3.1.3 Network Management Protocols

Managers and agents require some form of communication to issue their requests and responses. SNMP is the protocol used to issue requests and receive responses in a TCP/IP network. CMIP is the protocol used in ISO networks. CMIP and SNMP define:

Types of requests and responses that can be issued (for example, get, set, get response, and set response)

Who can issue requests and responses

Wording to use when issuing requests and responses (the syntax and encoding of each request and response)

How the requests and responses are exchanged (for example., using OSI or TCP/IP network protocols to pass the requests and responses back and forth)

Both SNMP and CMIP specify ASN.1 as the language used to encode and decode request and response messages.

Other management protocols besides CMIP and SNMP exist. These other protocols are used primarily to manage devices that existed before SNMP and CMIP became available and are referred to as legacy or proprietary protocols.

Transaction Language1 (TL1) is a network management protocol used for managing Telecommunication networks. It serves as a primary user interface between the Network Element and the Manager Application, and is used to operate, administer and maintain the network.

3.1.4 Management Information Base (MIB)

In addition to being able to pass information back and forth, the manager and the agent need to agree on and understand what information the manager and agent each receive in any exchange. This information includes:

The attributes or types of data that can be supplied by an agent to a manager

The operations or actions performed by an agent that can be requested by a manager

The behavior exhibited by the agent

The notifications or the types of unsolicited information an agent can send to a manager

This information varies for each type of agent. For instance, an SNMP agent running on a Synoptic hub will be described by one set of attributes and actions, and an SNMP agent running on a Cisco router will be described by a different set of attributes and actions.

The collection of this information is referred to as the management information base. The ISO standards organization defines a management information base in ISO/IEC 7948-4 as follows, "The conceptual repository of management information within an open system." A manager normally contains management information describing each type of agent the manager is capable of managing. This information would typically include Internet MIB definitions and ISO GDMO definitions for managed objects and agents. An agent typically presents (or contains) management information for one type of device, although this information can include descriptions and data for several types of devices.

For protocol like TL-1(Transaction Language-1), There is nothing like MIB standards .The TL1agent interprets the input messages and sends response

3.2.Functional Area of Network Management System:

Network management is the ability to control and monitor a computer network from a central location. The International Organization for Standardization (ISO) defined a conceptual model for describing the key functional areas of network management, which are described below.