Transcript kroenke_emis3_ch06

Chapter 6
Data Communications
What Is a Computer Network?
Network
• Collection of computers
• Communicate with one another over transmission line
Major types of network topologies
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Categories of computer networks
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What Are the Components of a LAN?
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Network components
•
•
Network interface card (NIC)
Transmission media – wired
or wireless
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Network Components
Transmission Media
•
•
UTP cable: Most
popular for wired
Ethernet networks
Types of UTP cable
― Cat 5E: Cheapest,
designed for 100 Mbps
― Cat 6: Designed to
support gigabit Ethernet
network
― Cat 6a: Designed for
ultra-fast Ethernet
networks
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UTP & RJ45
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Wireless Router
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Home Network
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Network Components
•
Routers and switches facilitate and control the flow of
data
― Router: Transfers packets of data between two or more
networks
― Switch: Receives data packets and sends them to intended
nodes on the same network
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LAN Protocol
IEEE 802.3 Protocol
Wired LAN
IEEE 802.11 Protocol
Wireless LAN
Most popular 802.11g (2010)
10/100/1000 Mbps Ethernet
Bluetooth
Protocol specifies hardware
characteristics, cables, and
how messages are packaged
and processed
Common wireless protocol for
transmitting data over short
distances—wireless mice and
keyboards, cell phones
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Connecting to the Internet
Wireless Internet Access
•
Mobile broadband: Connect to Internet through
cellular network to get 3G or 4G access.
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TCP/IP Architecture
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Application Layer Protocols
Hyper Text Transport Protocol (HTTP)
•Protocol used between browsers and web servers.
Simple Mail Transfer Protocol (SMTP)
•Used for email transmissions.
File Transfer Protocol (FTP)
• Used to move files over Internet.
• Web-Internet-based network of browsers and servers that
process http or https. When you use ftp or smtp, you are
using Internet, not web.
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TCP and IP Protocols
TCP or Transmission Control Protocol
•Breaks traffic up into pieces and send each piece
along its way
IP (Internet Protocol)
• Specifies routing of pieces of data communication
through networks that comprise any Internet
• Packet is a piece of a message that is handled by
programs that implement IP
• Router is a special purpose computer that moves packet
traffic according to rules of IP protocol
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IP Addressing
Public IP Addresses
•Identify a particular device on public Internet
•Public IP Addresses must be unique, worldwide
•Assignment controlled by ICANN (Internet
Corporation for Assigned Names and Numbers)
Private IP Addresses
•Identify a particular device on a private network,
usually on a LAN
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Public IP Addresses and Domain Names
IPv4 Supports (232) or 4,294,967,296 addresses
•Four decimal dotted notation like 165.193.123.253
IPv6 - Supports 2128 addresses
Domain name
•Unique name affiliated
with public IP address
URL (Uniform Resource
Locator)
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How Do Organizations Benefit From Virtual
Private Networks (VPNs)
Virtual private network
• Uses Internet or private network to create appearance of
point-to-point connections
• Uses public Internet to create appearance of private network
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IIUM VPN
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