Network Management

1
Network Management
2
Network Management Requirements

• Fault Management
• Accounting Management
• Configuration and Name Management
• Performance Management
• Security Management

3
Fault Management

• A fault is an abnormal condition that requires
  management attention (or action) to repair
• Fault is usually indicated by failure to operate
  correctly or by excessive errors
• Users expect quick and reliable resolution

4
Responding to Faults

• When faults occur, it is critical to quickly
• Determine exactly where the fault is
• Isolate the rest of the network from the failure
  so that it can continue to function without
  interference
• Reconfigure or modify the network to minimize the
  effect of removing the failed component(s)
• Repair or replace the failed components to
  restore the network to its initial state

5
Accounting Management

• Reasons for accounting management
• Internal chargebacks on network use
• User(s) may be abusing access privileges and
  burdening the network at the expense of other
  users
• Users may be making inefficient use of the
  network, and the network
• The network manager is in a better position to
  plan for network growth if user activity is known
  in sufficient detail.

6
Configuration Management

• Concerned with
• initializing a network and grace-fully shutting
  down part or all of the network
• maintaining, adding, and updating the
  relationships among components and the status of
  components themselves during network operation

7
Performance Management

• Issues of concern to the network manager include
• What is the level of capacity utilization?
• Is there excessive traffic?
• Has throughput been reduced to unacceptable
  levels?
• Are there bottlenecks?
• Is response time increasing?
• Network managers need performance statistics to
  help them plan, manage, and maintain large
  networks

8
Security Management

• Concerned with
• generating, distributing, and storing encryption
  keys
• monitoring and controlling access to networks
• access to all or part of the network management
  information
• collection, storage, and examination of audit
  records and security logs

9
Network Management Systems

• Collection of tools for network monitoring and
  control, integrated in these ways
• A single user-friendly operator interface for
  performing most or all network management tasks
• A minimal amount of separate equipment
• consists of incremental hardware and software
  additions implemented among existing network
  components

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Network Management System Architecture
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Components of the NMS

• All nodes run the Network Management Entity (NME)
  software
• Network control host or manager runs the Network
  Management Application (NMA)
• Other nodes are considered agents

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Network Management Entity

• Collection of software contained in each network
  node, devoted to the network management task
• Performs the following tasks
• Collect statistics on communications and
  network-related activities.
• Store statistics locally
• Respond to commands from the network control
  center
• Send messages to NCC when local conditions
  undergo a significant change

13
Indicators Reported by Network Monitors

• Service Parameters
• Availability
• Response Time
• Accuracy and Integrity
• Efficiency Parameters
• Througput
• Polling
• Utilization

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Simple Network ManagementProtocol (SNMP)

• Network Management Model
• Management station
• Management agent
• Management information base
• Network management protocol

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Role of SNMP
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Protocol Specification

• Transmission of a message
• Receipt of a message
• Variable bindings

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SNMPv2

• Released in 1992, revised in 1996
• Addressed functional deficiencies in SNMP
• Accommodates decentralized network management
• Improves efficiency of data transfer

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SNMPv3

• Released in 1998, addressed security deficiencies
  in SNMP and SNMPv2
• Does not provide a complete SNMP capability
  defines an overall SNMP architecture and a set of
  security capabilities for use with SNMPv2
• Provides three important services
  authentication, privacy, and access control