CT 1503
Network Operating Systems
Instructor: Dr. Najla Al-Nabhan
2014
Course Overview
Course Title: Networks Operating
Systems
Course Code: CT 1503
Course Level: Fifth
Course Co-requisite: CT1503
Lecture Time: Tuesday 9:00 am12:00 pm
Credit Hours: 3(3+ 0)
Course Instructor
Name
Dr. Najla
Al-Nabhan
Rank
Assistant
Professor
Office
Email
Number and Office Hours
Address
Location
Office #: 321
2nd Flour,
Sunday 12-3
Bldg 1,
Tuesday 12-3 nalnabhan@
Olishah
Wednesday 11- KSU.EDU.SA
Campus,
3
KSU
Course Website:
http://fac.ksu.edu.sa/nalnabhan/course/
Course Syllabus
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Course Syllabus
Aimed to impart
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Network operating systems (NOS):
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Definition,
tasks,
examples,
tools,
managing users’ accounts,
protocol setting,
and security.
Grading Overview
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Homework Assignments: 10%
Quizzes: 15%
Class Participation: 5%
Mid-terms: 30%
Final Exam: 40%
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One Quiz and/or tutorial per week, schedule will be announced soon
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Lecture 1: Network Operating Systems (NOS)
An Introduction
What is an Operating System?
• 2 kinds of a
software
– Application
Software
• Word processors,
database manager,
compiler, web
browser
– System Software
• Operating system
itself
• Bridges between the
hardware and users
Functions of Operating Systems (OS)
Resource management
• Memory management
• Device management
– Printer
– Hard drive
– display
• Process management
• Processor management (CPU time )
Operating Systems (OS) : Examples
Why OS was Born?
Batch processing
– Resident Monitor,
JCL, IOCS
Time Sharing Using Operating Systems
Operating Systems
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An operating system (OS) is software that manages
computer hardware and software resources and provides
common services for computer programs.
Operating systems form an essential component of the
system software in a computer system. Application
programs usually require an operating system to function.
Time-sharing operating systems schedule tasks for
efficient use of the system and may also include
accounting software for cost allocation of processor time,
mass storage, printing, and other resources.
Operating Systems
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For hardware functions such as input and output and memory
allocation, the operating system acts as an intermediary
between programs and the computer hardware, although the
application code is usually executed directly by the hardware
and will frequently make a system call to an OS function or be
interrupted by it.
Operating systems can be found on almost any device that
contains a computer—from cellular phones and video game
consoles to supercomputers and web servers.
Operating Systems: Examples
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Examples of popular modern operating systems include:
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Android, BSD, iOS, Windows Phone,
Linux, OS X, QNX,
Microsoft Windows, and IBM z/OS.
All these examples, except Windows, Windows Phone and z/OS,
share roots in UNIX.
Networks Operating Systems
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Network operating system refers to software that implements
an operating system of some kind that is oriented to computer
networking.
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For example, one that runs on a server and enables the server to
manage data, users, groups, security, applications, and other
networking functions.
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The network operating system is designed to allow shared file
and printer access among multiple computers in a network,
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typically a local area network (LAN), a private network or to other
networks.
Networks Operating Systems: Where to use?
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NOS can be used in:
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Routers, switches and hardware firewall.
PCs in Peer-to-peer networks
Client-server Architicture
Routers NOSs
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Network operating systems can be embedded in a router or hardware
firewall that operates the functions in the network layer (layer 3) of the OSI
model.
Examples:
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JUNOS, used in routers and switches from Juniper Networks,
Cisco IOS (formerly "Cisco Internetwork Operating System").
TiMOS, used in routers from Alcatel-Lucent
VRP (Versatile Routing Platform), used in routers from Huawei
RouterOS, software which turns a PC or MikroTik hardware into a dedicated router
ZyNOS, used in network devices made by ZyXEL.
ExtremeXOS, used in network devices made by Extreme Networks. Also called
EXOS.
Embedded Linux, in distributions like Openwrt and DD-WRT which run on low-cost
platforms such as the Linksys WRT54G.
Peer-to-Peer NOSs
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In a peer-to-peer network operating system users are allowed to share resources and
files located on their computers and access shared resources from others. This
system is not based with having a file server or centralized management source. A
peer-to-peer network sets all connected computers equal; they all share the same
abilities to use resources available on the network.
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Examples:
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AppleShare used for networking connecting Apple products.
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Windows for Workgroups used for networking peer-to-peer windows computers.
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Advantages
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Ease of setup
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Less hardware needed, no server needs to be purchased.
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Disadvantages
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No central location for storage.
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Lack of security that a client/server type offers.
Client/Server NOSs
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Network operating systems can be based on a client/server
architecture in which a server enables multiple clients to share
resources.
Client/server network operating systems allow the network to
centralize functions and applications in one or more dedicated
file servers.
The server is the center of the system, allowing access to
resources and instituting security.
The network operating system provides the mechanism to
integrate all the components on a network to allow multiple
users to simultaneously share the same resources regardless of
physical location.
Client/Server NOSs
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Examples:
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Advantages
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Novell NetWare
Windows Server
Banyan VINES
Centralized servers are more stable.
Security is provided through the server.
New technology and hardware can be easily integrated into the system.
Servers are able to be accessed remotely from different locations and types of
systems.
Disadvantages
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Cost of buying and running a server are high.
Dependence on a central location for operation.
Requires regular maintenance and updates.
Quiz
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next lecture