Network Management - Introduction

References

Communications Network Management, Kornel Terplan Prentice Hall 1992, 2nd ed.

Managing Inter networks with SNMP Mark A. Miller, M& T books 1999, 3rd ed.

SNMP, SNMPv2, SNMPv3 and RMON1 & 2, William Stallings, 3rd ed. Addison Wiley 1999

Telecommunications Network Management into the 21st century : techniques, standards, technologies, and applications, New York : IEEE Press

References - contd How to Manage your Network Using SNMP,

Marshall T. Rose and Keith McCloghrie The Simple Book, Marshall T. Rose A Practical Guide to SNMPv3 and Network 8.

Management, David Zeltserman, Prentice Hall. Network Management – Principles and Practice,

Mani Subramanian, Adddison Wesley Press Network Management, A Practical Perspective,

Allan Leinwand and Karen Fang Conroy, Addison Wesley

Introduction What is Network Management?Managing Networks - is the network Performing optimally Troubleshooting Reconfiguring - configuration Expanding Secure Accounting, Usage Planning

What if no NM?

What is the latest configuration? What are the systems and what is their

capacity?

Not up to speed? Where is the bottleneck? High delays under certain conditions? Why

is it happening? Permissions, access? Security?

Strategic Importance of Network and Network Management

1970s – decade of centralized networks 1980s –

More LANs Interconnected LANs Distributed computing

Contd.

Current Gigabit speeds SONET WANs Web based technologies Various architectures Wireless proliferation

NM Functional Groupings

Network Management

Network provisioning

Network Operations

Network Maintenance

Planning

Design

Fault Management /Service Restoration

Configuration Management

Performance/Traffic Management

Security Management

Accounting Management

Reports Management

Inventory Management

Data Gathering Analysis

Fault Management

Trouble ticket administration

Network Installation

Network Repairs

Facilities Installation and Maintenance

Routine Network Tests

Network Dependency

Business Commercial Education Research Defense Integration of these sectors

Network Dependency

Failure of networks Inefficient operation

Heavy Downtime costs and Loss

Factors affecting NM systems

Network Management

Growth of Networks

distributed architectures

Vendor population

Growing technologies

Business strategies

Growing users & demands

Complexity of Network Management

Management by Human effort

Automated tools

Large networks - heterogeneous equipment

§       cost and complexity higher

§       need for standardized tools

management Staff

Is NM crucial?

Better control – higher level of network performance

Better performance – higher productivity Higher productivity – financial stability

and improvement (Continuous improvements in network

management necessary)

contd

How to cope with new applications? New Systems? Controlling complexity Improving services Balancing needs Reduce downtime Controlling costs

NM? CEO: financial management of the corporate

communications network USER Availability Reliability Performance Stability Security Simplicity in accounting

Critical Success Factors for NM

Process and procedures Steps and guidelines on how to use the

necessary tools to execute network management

Instruments Hardware & software for data collection

and processing Human Resources

NM personnel

Process and Procedures

Configuration Management Fault Management Performance Management Security Management Accounting Planning

Configuration Management

Middle and long range activities for controlling physical, electrical and logical inventories maintaining vendor files supporting provisioning and order

processing managing changes distributing software

Fault Management

Dynamically maintain network service level High availability Quick recognition of problems & performance

degradation Log control & information distribution Fault Isolation Reconfigure / Modify to minimize impact Repair /Replace failed components

Performance Management

Ongoing evaluation of network – service level maintenance

Identify bottlenecks (potential) Check level of capacity/ utilisation? Check delays Check for unusual network behaviour

Security

Ongoing protection of network Protection of Network Components Entry to network Access to Services Transfer of information from network Risk analysis – minimizing Implementing security plans Monitoring Success of strategies

Accounting

Process of Collecting Interpreting Reporting on

Costing and charging oriented information on resource usage

Processing of accounting records, bill verifications, charge back procedures

contd

Resources subject to accounting Communication facilities Hardware usage Software usage Other services

Security and Accounting depend on Company Policies

Planning Off line management, based on collected statistics,

corporate level decisions, network designers, user requirements & demands

Involves dimensioning a networks Depends on

Network traffic Resource utilization Networking requirements Technological trade-offs Estimated growth – technology Growth of user population

Monitoring and Control

Network Monitoring Observing and Analysing the status and

behaviour of the end-systems, intermediate systems and sub-networks

Three major functions Design monitoring mechanism Access information for monitoring Apply monitored information

Types of monitored information

Static Information Related to current network configuration Infrequent information change

Dynamic Information Related to events

Statistical Derived from dynamic information

Relationship Calls Blocked

Packet Loss Time Delay

Throughput

State Variables

Event Variable

Ssystem_Buffer Server details

System_Info

Status sensor Event Sensor

Derived_Status_sensor

Statistical information

Dynamic Information

Static Information

Sensor database

Conf. database

Sensor activation and data collection

Abstraction of state and event variables

Monitoring and Control

Network Control Modifying parameters and causing actions to be

taken by the end systems, intermediate systems, sub-networks

Physical and Logical Network management

Physical Problem detection Failure notification on

Physical entities– Circuits

– Devices

– Multiplexers etc

Contd.

Logical Monitoring and management of

Logical Connections Session awareness Traffic flow monitoring

In summary NM

NM is continuing process Data identification Extraction Collection Maintenance Analysis Interpretation

For Control and Management

NM architecture - Manager / Agent Model

Management System Managed System

Manager Process

Management Database

Management Database

Managed Objects

Agent Process

Commands

Responses

Notifications

Contd..

Management System Houses a Manager Application Management Database

Manager Application Interface between Network manager (human) and the

devices being managed Could be GUI based

There could be a number of manager applications and Management Systems

Contd..

Managed System Has the Agent process Managed Objects Management Database Management Information Database

There could be a number of Managed Systems

Contd..

Agent Process Collects statistics on communication and

network related activities Store statistics locally Respond to commands from network

Transmit collected statistics to network control centre

Change a parameter Provide status information Generate artificial traffic pattern to perform a test

Contd..

Agent Process Send messages to the Manager Process when

local conditions undergo significant changes Notifications

Contd.. Monitoring Agent

Module that generates summaries and statistical analyses of management information

Management Application

Manager Function

Agent Function Managed Objects

Management Application

Manager Function

Agent Function Managed Objects

Agent Function

Managed Objects

Monitoring Agent

Managed Objects

Entities which need to be monitored and controlled TCP connection Packets Time CPU Link

Management Information Base (MIB)

MIB is a virtual data Information base. It is compiled into the manager and Agent application. It is static

Management database contains the measured values associated with the Managed object. It is dynamic

MIB structure

Tree structure with root Branches – managed objects by logical

categories leaves – managed objects

Management Protocol

Sets up communication protocol between manager, agents and managed objects Commands Responses Notifications

Techniques of monitoring

Polling Request-response interaction Manager queries for variables Agent responds Request reports with matching criteria

Techniques of monitoring

Event Reporting Agent Initiated Manager is listener Periodic Events On occurrence of significant or unusual event

Polling or Event Reporting

Either or combination Amount of traffic generated Robustness in critical situations Time delay in notification Amount of processing in managed devices

Typical Manager Agent configuration

Network Manager

Router Agent

Host Agent

Router MIB Host MIB

Global MIB

NM in the OSI model

NM resides at the Application layer

Application

Presentation

Session

Transport

Network

Data Link

Physical

Network Management Application

Internetwork Management

Local Network Management

Local Network

Connectivity

Internetwork Connectivity

Logical Connectivity