Network Management - Introduction

References Communications Network Management, Kornel Terplan Prentice Hall 1992, 2 nd ed. Managing Inter networks with SNMP Mark A. Miller, M& T books 1999, 3 rd ed. SNMP, SNMPv2, SNMPv3 and RMON1 & 2, William Stallings, 3 rd 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 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

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

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

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

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

NM in the OSI model NM resides at the Application layer