Network Management
•Network Management:
–Overall administration from,
•Initial setup/installation to,
•Continuous maintenance of data communication network.
–Normally done by people called:
•Network Managers,
•Who will be required by,
–Every organization whether big or small.
–Examples:
•Network Manager at a Cyber Café.
•Network Manager at an ISP such as Reliance.
•Network Manager at a private firm such as Bank.
•Network Manager in a Government organization such as
PGVCL.
Network Management
•Tasks of a Network Manager:
–Apart from managing devices such as:
•Servers, Clients, Computers, Terminals, Modems, Multiplexers,
Switches, Hubs, Routers, Wires etc.
–The tasks of Network Managers might be different depending
on the network for which they are responsible:
•WAN Managers:
–Interact with long-distance common carriers, local telephone
companies and service providers.
–Deal with issues involving telephone circuits, fiber-optic cabling,
and satellite transmission.
•LAN Managers:
–Deal with a network within a single building or many buildings in a
single city.
–Responsible for selecting the appropriate network design including,
»Topology, communications protocol, communications media
needed to connect clients and servers; monitoring for
performance and security; and managing network accounts.
Network Management
•Network Management:
–Managers after installing a network once,
•Cannot take a sigh of relief afterwards because,
•Their work is going to increase and not decrease from
there.
–Examples:
•Think about expansion of network when users are going
to increase in future where,
–One user shouting for not having connectivity/access,
–Other user might complaining for slower response,
–Third user shouting for his/her PC not responding,
–Fourth user complaining for over-billing and,
•On top of all that,
–No one actually understanding / trying to understand the
problem of a Network Manager.
Network Management
•Network Management:
–Basic questions are:
•Functions of Network Management:
–What are you supposed to manage in a Network?
•Objectives of Network Management:
–Why are you supposed to manage a Network?
•Meeting the objectives:
–How are you supposed to manage a Network?
Functions of Network Management
•Network Management & the ISO Model:
–ISO defines 5 functional areas of network systems
management:
•Configuration Management:
–Set up and configure a network as per the needs of the
organization so that authenticated/valid users can access the
network.
•Performance Management:
–Ensure that network always performs and there are no complaints
from users regarding the performance of the network.
•Fault Management:
–Ensure that network does not fail and if it fails it does not fail too
often.
•Security Management:
–Ensure that unauthorized/invalid users cannot access the network
and,
–Also ensure that authorized users also cannot access
unauthorized content.
•Accounting Management:
–Charge valid users according to the usage (bandwidth / time) of
the network.
Manager of a Cyber Café.
Functions of Network Management
•Network Management & the ISO Model:
–Also known as:
•FCAPS.
–Fault, Configuration, Accounting, Performance,
Security.
–All the above areas could be automatically
managed using:
•Readily available Softwares such as:
–HP OpenView, CiscoWorks2000, Network Associates
Sniffer Total Network Visibility, IBM Tivoli Performance
and Availability Software.
Network Management Softwares
Network Management Softwares
Network Management Softwares
Objectives of Network Management
•Main objective of network management is:
–User Satisfaction.
•Performance of the network.
–Hint: Response Time, Imagine a bank teller waiting, Emergency
situations.
•Availability & Reliability of the network.
–Hint: Minimize impact during maintenance, Backup components /
AMC.
•Information availability.
–Hint: Open communication with users, Schedule of preventive
maintenance.
•Network uptime.
–Hint: Patch around the Problem, Replacement, Repair
•Backup facilities.
–Hint: Software Backup (RAID), Hardware Backup (PGVCL).
•Cost effectiveness.
–Hint: Prior Planning for Expansion in future.
Objectives of Network Management
•User Satisfaction:
–Performance:
•User’s primary measure of performance is:
–Response Time.
–It is,
»Amount of time it takes for a full screen of data to return to the user
after he or she presses the ENTER key.
•In most networks,
–Users specify the desired response time when the network is designed.
–Example:
»A bank teller many not want to wait longer than 2 seconds for the
customer’s account information to display on a screen after entering the
account number.
•If the network slows down and the expected response time lengthens,
–The user may start pressing additional keys on the keyboard and,
–The application may not be able to handle the additional keying and may
react negatively by returning the incorrect data or by logging the user off the
system entirely.
•Response time is also important in emergency situations in which,
–A fast response is critical such as,
»A fire department, 108 ambulance service, US homeland security.
Objectives of Network Management
•User Satisfaction:
–Availability & Reliability:
•Imagine a very nice performance but highly inconsistent.
•All the components needed to complete a transaction should be
available.
•There will be unavailability due to preventive maintenance that is
needed on a periodic basis to ensure continued operation of the system.
–Usually all applications are taken offline during this time so the hardware can
be checked.
–To minimize the impact on the user,
»These operational downtimes can be scheduled when it affects the
fewest number of users, such as on a weekend or late at night.
•Is also affected by 2 parameters:
–Mean Time Between Failures (MTBF):
»Hardware manufacturers use this measure to indicate the average
length of time a component will operate before it fails.
–Mean Time To Repair (MTTR):
»Average amount of time needed to fix a component that fails.
•These 2 parameters decide whether,
–A network manager needs to stock backup components or take an AMC
(Annual Maintenance Contract)
Objectives of Network Management
•User Satisfaction:
–Information availability:
•The network manager must make information available and have,
–An open line of communications with the network users at all times.
•If users are kept informed about the status of the network, then,
–Their frustration level will be lower when something unforeseen happens to
affect the network.
•Users should be kept informed of events affecting the network, such as,
–Scheduled downtimes.
•In fact the network manager should work with users when scheduling
such times so as,
–A minimum number of users are affected.
•Network manager also can educate the users about peak operating
times.
–When the network is loaded heavily, performance degrades.
–If the users are aware of this, large batch jobs can be scheduled for times
when fewer people are using the network.
•Users need to know whom to contact about the network.
•Example:
–If personnel changes occur at a help desk, a central location for users to call
for help with network problems, the users should be informed of this fact.
Objectives of Network Management
•User Satisfaction:
–Network uptime:
•If the network fails after all preventive measures
have been taken,
–The network manager must ensure that service is
restored as quickly as possible.
–3 methods for fixing the network are available:
»Patch around the problem
»Replacement
»Repair
Objectives of Network Management
•User Satisfaction:
–Backup:
•Software Backup:
–Software must be backed up on another medium so that,
»If the original medium fails,
»The software can be copied or used from the other
source.
–RAID (Redundant Array of Independent Disks) storage
method is used which uses,
»More than 1 hard disk where the data is written to.
•Hardware Backup:
–Design extra circuits into the network so that,
»If the primary one fails, the backup can be used.
Objectives of Network Management
•User Satisfaction:
–Cost-Effectiveness:
•Can be achieved using:
–Prior Planning and Expansion:
•Planning is one of the critical parts of designing a
network.
•2 methods of buying equipment are:
–Company buys only the equipment required as of today.
»Lower immediate cost but can result in higher costs for
future expansion.
–Buy equipment to meet current and future needs at the
time the network is installed.
»Higher initial costs, but the cost of expanding the
network will be lower.
Meeting the Objectives
•Meeting the Objectives:
–Staffing.
•Recruiting qualified staff to achieve the needs.
–Network Analysis.
•Analyze the network for performance and,
–Tune the network according to the needs.
Meeting the Objectives
•Meeting the Objectives:
–Staffing:
•Network managers should invest time and effort
in staffing that is,
–Selecting qualified technicians, help desk personnel
and network administrators.
•A good staff is composed of,
–Dedicated and knowledgeable employees with a,
–Low attrition (wear and tear) rate.
•A network manager also needs a staff with
various kinds of Talents and Skills such as:
–Design and Configuration Skill.
–Diagnosis Skill including Troubleshooting etc.
Meeting the Objectives
•Meeting the Objectives:
–Network Analysis:
•Network Statistics:
–Information about the network is collected in the form of,
»Network statistics that can be summarized and
reported for analysis of the network.
–Statistics are gathered by,
»Hardware devices,
–And reported by,
»Statistical softwares.
•Network Changes:
–Once all the data/statistics are collected,
»Tune (Make changes) to the network as per the needs.
–Change the parameters and then,
»Monitor the system to see what effect the changes
have on response time.