2. NETWORKING AND COMMUNICATION TRENDS
Convergence of telephones and computer networks (and internet):
Examples are smartphones
Cable companies now offering voice service and Internet access.
Broadband:
High-speed connections provided by telephone and cable TV companies
running at 1 to 15 million bits per second
Broadband wireless:
Voice and data communication as well as Internet access are increasingly taking
place over broadband wireless platforms
3. WHAT IS A COMPUTER NETWORK?
Two or more computers connected together
Major components in a simple network
Client computer
Server computer
Network interface Card (NIC)
Connection medium
Network operating system (NOS)
Hub or switch
Routers
Device used to route packets of data through different
networks, ensuring that data sent gets to the correct
address
4.
5. Corporate Network Infrastructure
Today’s corporate network
infrastructure is a collection
of many different networks
from the public
switched telephone network,
to the Internet, to corporate
local area networks (LANs)
linking workgroups,
departments, or office floors
6. KEY DIGITAL NETWORKING
TECHNOLOGIES
Client/server computing
Clients linked through network controlled by network
server computer
Method of slicing digital messages into parcels (packets), sending
packets along different communication paths as they become available,
and then reassembling packets at destination
Packet Switching
7. KEY DIGITAL NETWORKING
TECHNOLOGIES
TCP/IP and connectivity
Transmission Control Protocol (TCP), which handles the
movement of data between computers.
Four layers:
1. Application layer
2. Transport layer
3. Internet layer
4. Network interface layer
8. SIGNALS: DIGITAL vs. ANALOG
There are two ways to communicate a message in a network:
Analog signal
A continuous waveform that passes through a communications medium
Digital signal
A discrete, binary waveform, rather than a continuous waveform
Modem converts digital signals into analog signals
9. TYPES OF NETWORKS
Metropolitan Area Network (MAN)
• Large network that connects
different organizations
Wide Area Network (WAN)
• Internet among the whole world
Local Area Network (LAN)
• Contains printers, servers and computers
• Systems are close to each other
• Contained in one office or building
• Organizations often have several LANS
Campus Area Network (CAN)
Peer-to-peer network
12. PHYSICAL TRANSMISSION MEDIA
Twisted Wire
Coaxial Cable
TV cable wire
Thicker
Fiber Optics and Optical Networks
Data is transmitted with light pulses
Speeds up to 100 Gbps
13. PHYSICAL TRANSMISSION MEDIA
Wireless transmission media and devices
Microwave
Satellites
Cellular telephones
BP’S SATELLITE
TRANSMISSION
SYSTEM
Transmission Speed
• Hertz
• Bandwidth
14. THE GLOBAL INTERNET
What is the Internet?
World’s most extensive, public communication system
Internet Addressing and Architecture
The Domain Name System
Hierarchical structure
Top-level domains
Internet Architecture and Governance
Network Service Providers
The Future Internet: IPv6 and Internet2
15. DNS is a
hierarchical
system with a root
domain, top-level
domains, second-
level domains, and
host computers at
the third level
19. Voice over IP
Unified Communications
Switching back-and-forth between different communication modes
Virtual Private Network (VPN)
A secure, encrypted, private network
configured within a public network
VPN secures the connection by using a ‘tunnel’
20. World Wide Web (www)
HTML (Hypertext Markup Language):
Formats documents to display on Websites
Hypertext Transfer Protocol (HTTP):
Communications standard used for transferring Web pages
Uniform resource locators (URLs):
Addresses of Web pages
Search engines
Firefox, Google Chrome, Opera etc
PageRank
An algorithm used by Google
Shopping Bots
Use intelligent agent software to search Internet for shopping info.
21. Web 2.0
Four defining features
1. Interactivity
2. Real-time user control
3. Social participation
4. User-generated content
Technologies and services behind these features
• Cloud computing
• Blogs & Vlogs
• Mashups & widgets
• Wikis
• Social networks
Web 3.0, will be the future!
Semantic web (giving meaning to the web)
22. The Wireless Revolution
Cellular systems (mobile phones network)
Wireless Computer Networks And Internet Access
Bluetooth
802.15 wireless networking standard
Creates small Personal Area Networks (PAN)
Useful for quickly sharing files across platforms
Wifi (802.11)
PCs, mobile phones, smart TVs etc can connect to the internet using
router for signals
Hotspot: access points providing wireless Internet access in a public place
24. Radio Frequency Identification (RFID)
A powerful technology for tracking the movement of goods throughout the
supply chain
Use tiny tags with embedded microchips containing data about an item
and location, and antenna
The Wireless Revolution
25. The Wireless Revolution
Wireless Sensor Networks (WSN)
Networks of many interconnected wireless devices embedded into
physical environment to provide measurements of many points over
large spaces
Devices have built-in processing, storage, and radio
frequency sensors and antennas