Transcript Network Management - Introduction

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
Fault Management /Service Restoration
Planning
Configuration Management
Design
Network
Maintenance
Fault Management
Trouble ticket
administration
Performance/Traffic Management
Network Installation
Security Management
Accounting Management
Reports Management
Inventory Management
Data Gathering Analysis
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
Growing
technologies
Business
strategies
Vendor
population
Network
Management
Growing users
& demands
distributed
architectures
Growth of
Networks
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
Statistical
information
Calls Blocked
Time Delay
Packet Loss
Throughput
Abstraction of state and event variables
Dynamic
Information
State Variables
Event Variable
Sensor activation and data collection
Static Information
Sensor database
Ssystem_Buffer
Server details
System_Info
Status sensor
Event Sensor
Derived_Status_sensor
Conf. database
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
Manager Process
Management
Database
Managed System
Commands
Responses
Notifications
Agent
Process
Management
Database
Managed
Objects
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
Management
Application
Manager
Function
Manager
Function
Monitoring Agent
Agent
Function
Managed
Objects
Agent
Function
Managed
Objects
Agent
Function
Managed
Objects
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
Global MIB
Router
Agent
Router MIB
Host
Agent
Host MIB
NM in the OSI model
Application
Presentation
Logical
Connectivity
Internetwork
Connectivity
Local
Network
Connectivity
Network
Management
Application
Session
Transport
Network
Data Link
Internetwork
Management
Local Network
Management
Physical
 NM resides at the Application layer