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Lecture

ITM 102 Lecture Notes - Local Area Network, Digital Subscriber Line, Internet Service Provider


Department
Information Technology Management
Course Code
ITM 102
Professor
Franklyn Prescod

Page:
of 5
Chapter 7
Networking and Communication Trends
Convergence:
Telephone networks and computer networks converging
into single digital network using Internet standards
E.g. cable companies providing voice service
Broadband:
More than 60% Canadian Internet users have broadband
access
Broadband wireless:
Voice and data communication as well as Internet access
are increasingly taking place over broadband wireless
platforms
What is a computer network?
Network Interface Card (NIC)
Network Operating System (NOS)
Routes and manages communications on the network and
coordinates network resources
Dedicated server computer
Hubs
Routers
Networks in Large Companies
Hundreds of local area networks (LANs) linked to firm-wide
corporate network
Various powerful servers
Web site
Corporate intranet, extranet
Backend systems
Mobile wireless LANs (Wi-Fi networks)
Videoconferencing system
Telephone network
Wireless cell phones
Key Digital Networking Technologies
Client/server computing
Packet Switching
TCP/IP and Connectivity
Client/Server Computing
Client/server computing is a distributed processing model in which
some processing power is located within small, inexpensive client
computers
The clients are linked to one another through a network that is
controlled by a network server computer
The server sets the rules of communication for the network and
provides every client with an address so others can find it on the
network
Packet Switching
Messages are first broken down into small bundles of data called
packets
Packets are sent along different communication paths as paths become
available
Packets are reassembled once they reach their destinations
TCP/IP and connectivity
Connectivity between computers enabled by protocols
Rules that govern transmission of information between
two points
Transmission Control Protocol/Internet Protocol (TCP/IP)
Common worldwide standard that is basis for
Internet
Department of Defense reference model for TCP/IP
Four layers
1. Application layer
2. Transport layer
3. Internet layer
4. Network interface layer
Signals: digital versus analog
Digital: discrete, binary waveform
Analog: continuous waveform, typically used for voice
A modem (modulator - demodulator) converts from one state to the
other
Types of Networks
Local Area Network (LAN)
Campus Area Network (CAN)
Metropolitan Area Network (MAN)
Wide Area Network (WAN)
Physical transmission media
Twisted wire
Coaxial cable
Fibre optics and optical networks
Wireless transmission media
Microwave, satellite, cellular
Transmission speed (hertz, bandwidth)
What is the Internet?
Links hundreds of thousands of individual networks all over the world
Most homes connect to the internet by subscribing to an Internet
Service Provider (ISP)
Digital Subscriber Line (DSL)
Cable Internet connections
T1 and T3 lines
Internet Addressing and Architecture
The Domain Name System
Every device connected to the Internet has a unique 32-bit
numeric IP address
A Domain Name System (DNS) converts IP addresses to English-
like domain names
The domain name is the English-like name that corresponds to
the unique 32-bit numeric IP address
Internet Architecture and Governance
The Future Internet: IPv6 and Internet 2
IPv6: allows 128 bit addresses, a quadrillion possible addresses
Internet2: consortia of agencies working to provide an new robust and
high-bandwidth version of the Internet
Internet Services and Communications Tools
Email
Chatting and Instant Messaging
Newgroups
Telnet
File Transfer Protocol (FTP)
World Wide Web
Voice over IP (VoIP)
delivers voice in digital form over the Internet
Unified Communications
integrates all communications (voice, data, etc.) into one stream
to allow user to switch back and forth
Virtual Private Networks (VPN)
secure, encrypted private network for use internal to an
organization
The Web
Hypertext Transfer Protocol (HTTP)
Communications standard used for transferring Web
pages
Uniform resource locators (URLs)