DOCUMENTING IT NETWORK – Part 1

Following has been compiled by Ms.Vidushi Wahal a 4th year B.Tech (IT).

Network Management system is an essential part of many systems. These are
collectively known as Operations, Administration, Maintenance and Provisioning.
Three categories or classes of management information have been defined:
1. Configuration Management.
2. Performance Management.
3. Fault Management.
Interfaces have been defined for each category between information gathering
agent (Element Manger) and information collecting agent (Network Manager).
These interfaces are called Integration Reference Points (IRP).

Architecture
Element Managers or Agents are deployed with the Network Elements or are
embedded with the Network Elements. Network Manager requests the
information about the Network Elements from their respective Agents and these
Agents interact with Network Elements and respond to Network Manager’s
requests with requested information. Agents also monitor different parameters
of Network Element and generate the Messages known as TRAPS or INFORMS for
the Network Manager in case of some error, warning or to notify some event.

Network Manager
Network Manager is responsible for the management of Network Elements by
interacting with their respective Element Managers or Agents. Network Manager
can manage multiple Agents in the network through SNMP protocol. The
information or parameters of a Network Element that will be managed are
defined in the form of Management Information Base (MIB) Variables using
Abstract Syntax Notation (ASN).

Network Manager Components
The main components of Network Manager are:
1. SNMP Manager
2. MIB Module
3. Database Module
4. Data Model / Presentation Interface
5. IRP Management
6. Trap Service
The following diagram shows the logical placement of above mentioned
components in the
Network Manager:

SNMP Manager
SNMP Manager handles all the SNMP protocol specific operations, and directly
communicates with the Agents hiding the SNMP protocol level details from the
upper layers. All the management requests made by Network Manager to the
Agents are translated into SNMP Protocol Data Units (PDUs) at this layer are the
responses from the Agents are translated to simple and understandable
management information for the upper layers.
MIB Module
MIB Module holds the MIB related data for the Network Manager. It loads the
management information from the MIB files and arranges them in high
performance data structures for fast retrieval.

Database Module
The Database Module provides the functionality for database interaction.
Network Manager stores the management information in the database using the
interfaces provided by Database Module.
Data Model / Presentation Interface
The Data Model / Presentation Interface is the layer that implements the
Network Manager application logic. It holds the caches of the variable values
fetched from the Agents and format the management information for
presentation layer. This layer also implements the logic to communicate with the
Agents.

IRP Management
IRP Management is a logical layer that logically separates the management
information in
Network Manager. There are three IRPs :
* Configuration Management
* Performance Management
* Fault Management
Trap Service
Trap Service is the component of Network Manager that listens for the TRAP or
INFORM messages from the Agents. It is responsible for handling these messages
and generating the response messages if necessary.

More to come in Part 2…