Transcript Slide 1
Chapter 1: Computer
Networks
IB 300: Advanced Computer
Sciences.
Professor: Nabil Elmjati
Introduction
Computer network
Computers connected together
Purpose: Exchanging resources and information
Just about any kind of information can be sent
Examples: Television and radio signals, voice,
graphics, handwriting, photographs, movies
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Basic Networking Concepts
Computer network
Set of independent computer systems connected
by telecommunication links
Purpose: Sharing information and resources
Nodes, hosts, or end systems
Individual computers on a network
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Basic Networking Concepts
Node: A Node is a connection point. In a physical Network, it is an
electronic device that is attached to a network and is capable of
sending, receiving and forwarding information over a
communication channel (Network)
Host: Any Computer connected to a network is considered a host.
Communication Links
Switched, dial-up telephone line
A circuit is temporarily established between the
caller and callee
Analog medium
Requires modem at both ends to transmit
information produced by a computer
Computer produces digital information
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Communication Links (continued)
Dial-up phone links
Transmission rate: 56,000 bps (56 Kbps)
Broadband
Transmission rate: Exceeding 256,000 bps (256
Kbps)
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Communication Links (continued)
Options for broadband communications
Home use
Digital subscriber line (DSL)
Cable modem
Fiber Optics
Commercial and office environment
Ethernet
Fast Ethernet
Gigabit Ethernet
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Transmission Time of an Image at Different Transmission Speeds
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Communication Links (continued)
Wireless data communication
Uses radio, microwave, and infrared signals
Enables “mobile computing”
Types of wireless data communication
Wireless local access network
Wireless wide-area access network
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Local Area Networks
Local area network (LAN)
Connects hardware devices that are in close
proximity
The owner of the devices is also the owner of the
means of communications
Common wired LAN topologies
Bus
Ring
Star
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Figure 1.4
Some Common
LAN Topologies
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Local Area Networks (continued)
Ethernet
Most widely used LAN technology
Uses the bus topology
Two ways to construct an Ethernet LAN
Shared cable
Hubs: The most widely used technology
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An Ethernet LAN Implemented
Using Shared Cables
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Figure 7.6
An Ethernet LAN Implemented Using a Hub
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Wide Area Networks
Wide area networks (WANs)
Connect devices that are across town, across the
country, or across the ocean
Users must purchase telecommunications
services from an external provider
Dedicated point-to-point lines
Most use a store-and-forward, packet-switched
technology to deliver messages
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Typical Structure of a Wide Area Network
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What is an IP Address:
An Internet Protocol address (IP address) is a
numerical label assigned to each device (e.g.,
computer, printer) that is part of a Computer
Network.
Example of IP address: 192.168.1.1
There are two types of IP addresses: Static and
Dynamic.
Static vs Dynamic
Static IP: A fixed IP that is permanently assigned
to a host.
Dynamic IP: A temporary IP that expires when
the host goes offline, and changes the next time
the host connects to the network.
How to know your IP address?
Local IP Address: By running the CMD command in
windows and typing: “ipconfig” in the terminal, then
hitting enter.
Public IP (given by the ISP): You can either visit a site such
as http://whatismyipaddress.com/
Or access your router to find out the actual IP address.