4. The Need For Network
• The cold war
• Sharing Information
• Delocalization of Data
• Pooling of resources
• Data protection
• Remote access
• Communication and collaboration
5. Advanced Research Projects
Agency (ARPA)
• ARPA in 1958 established to fulfill the
needs mentioned earlier
• The result: ARPANET (1968)
• First ARPANET established between 4
computers (1969)
6. ARPANET
The Eve of internet
• The 1st Multi-node network
• Global Network
• TELNET
• File Transfer
• EMAIL
8. Internetworking
• The process of linking a collection of networks
is called internetworking
• This term is where the internet got its name
• The term internet was officially adopted in
1983.
• More commonly referred to as the Net
9. The World Wide Web
• 1992- no web yet; NEWSNET news groups and
email
• World Wide Web protocol released by CERN
• Based on HTML
• Made internet graphical
• The reason for the popularity of internet
10. The Web's historic logo designed
by Robert Cailliau
Inventor : Sir Tim Berners Lee
Launch year : 1990
Company : CERN
11. WWW- The Rise Of The Internet
• 1977: 111 hosts on Internet
• 1981: 213 hosts
• 1983: 562 hosts
• 1984: 1,000 hosts
• 1986: 5,000 hosts
• 1987: 10,000 hosts
• 1989: 100,000 hosts
• 1992: 1,000,000 hosts
• 2001: 150 – 175 million hosts
• 2002: over 200 million hosts
• By 2010, about 80% of the planet will be on the Internet
12. WWW vs. Internet
• The Internet is the actual network. The World
Wide Web is something you can do with it.
You can do other things with it, too
• In other words, internet is the ocean while
www is the ship
• Protocols other than http are not the web, eg.
Bittorrent, emule etc
13. Protocols
How computers talk to each other
• Accepted means of communication
• Protocol
• Is an agreed upon format for transmitting data
between two or more devices
• A set of formal rules for transmitting data
14. TCP/IP
• Open-standard for communicating on the
Internet
• Every network in existence today relies on
TCP/IP
• TCP converts data into packets
• Email and file sharing, remote login
15. IP-Internet Protocol
• Every machine on the Internet has a unique identifying
number, called an IP Address.
• A typical IP address: 216.27.61.137
• Computers understand binary, the same ip address in binary:
11011000.00011011.00111101.10001001
• The four numbers in an IP are called octets and can contain
numbers from 0-255
• Almost 4.3 billion ip addresses
• Still they are running out
16. Domain Name System(DNS)
The phonebook of the internet
• Translates the human friendly names into IP
addresses
• For example : www.yahoo.com
• Request sent to .COM DNS server
• .COM DNS server returns address for servers
containing address for www.yahoo.com
• Request sent to the server again, server
returns the ip of www.yahoo.com
17. The internet Backbone
• Speed of ARPANet backbone no longer
sufficient
• National Science Foundation (NSF) created a
new high-speed network NSFNet
• It was a T1 line that connected 170 smaller
networks together and operated at 1.544
Mbps
18. The Present
How can you connect to the internet!
Wired Wireless
• Dial up • Satellite connection
• ISDN • Gprs/EDGE
• Cable • CDMA/EVDO
• DSL • Wimax
19. Dial-up Internet
• One of the most popular connections in the near-
past
• Operates on phone cables
• The modem dials the ISP(internet service
provider)
• Maximum Data Transfer up to 56Kbit/s
• Uses the standard analogue frequency
• Phone line cannot be used while online
• Becoming obsolete with the advent of DSL and
Cable internet
20. Integrated Services Digital Network
(ISDN)
• Operates on ordinary copper wires
• Simultaneous transmission of DATA and voice
• Digital transmission of data
• Data transfer rate up to 128 Kbit/s
• Mostly used by broadcast industry
21. Digital Subscriber Line(DSL)
• Provides digital transmission of data over the
wires of a telephone network
• Data transfer rate range from 256kbit/s to
30mbit/s
• “Always on” connection
• Started the broadband era
22. Asymmetric DSL (ADSL)
• Based on the fact that internet users
download more than they upload
• Distance sensitive technology
• The signal quality decreases as the connection
length increases
• A ratio of 1-10 between download and upload
is used
• The DSL connection we use in Pakistan is
mainly ADSL
23. How it works?
• DSL works by utilizing the extra unused capacity of
phone lines
• Human voice normally has a frequency between 0-
3400 Hz
• Voice is given its own channel from 0-4KHz
• The whole channel is divided into 247 separate
channels each 4KHz wide
• Each channel is monitored and the one with the best
signal strength is used for data transmission
• Can be thought of 247 separate phone lines, and the
one with the best signal quality is used
24. Cable Internet
• Uses cable television(CATV) infrastructure
• Requires a cable modem and a cable modem
termination system (CMTS)
• Connected via coaxial cable or Hybrid Fiber Coaxial
(HFC)
•Downstream (400-100)Mbps & upstream (384 Kbps-20
Mbps)
• Downstream requires 6 MHz channel and upstream 2
MHz
25. Satellite Internet Access
• Internet access via geostationary and low earth orbit
(LEO) satellites
• Requires
- a dish
- two modems (uplink and downlink)
- coaxial cables b/w dish and modem
Uses IP multicasting technology
• Upload speed is 1/10th of 500 Kbps download speed
• 10 times faster than normal modem
•Useful for rural internet users
26. GPRS/EDGE
GPRS
• Packet oriented wireless communication service
• Available to users of 2G cellular systems
• Based on Global system for mobile communication (GSM)
• Data rates of 56-114 Kbps
• Services offered
- “Always on” internet access
- Multimedia messaging service (MMS)
- Push to talk (PTT)
- Instant messaging (IM)
- Wireless application protocol (WAP)
- Point-to-point (P2P) service
27. GPRS/EDGE
EDGE
• Backward compatible digital mobile phone technology
• Is an upgrade of GPRS
• Considered a 3G radio technology
• Provides more than three-fold increase in capacity and
performance of GPRS/GSM
• Uses the techniques of GMSK and 8PSK for transmission
• Carries a bandwidth of 236.8 Kbps (4 times of GPRS)
28. WiMAX
• Worldwide interoperability for microwave access
(WiMAX)
• Provides fixed and fully mobile internet access
• Based on 802.16 standard
• Can provide BWA for up to 30 miles for fixed stations and
3-10 miles for mobile stations
• Similar to Wi-Fi
• Has higher speed and greater transmission range
29. The Future of the internet
• IPv6
• Cloud computing
• internet2
• Broadband Over power line
• Beyond Broadband, Completely Wireless
30. IPv6
Why do we need it?
• IPv4 can provide 4.3 billion unique addresses
• Large blocks of addresses are reserved and are
unavailable
• The addresses are running out, most likely by
2012
• A new standard is to be adopted
31. IPv6
The savior of the internet
• Uses a 128 bit address(IPv4 uses 32 bits)
• Uses hexadecimal system instead of he
decimal
• The total addresses are 2^128 that’s about
3.4x10^38 addresses
• A typical IPv6 address:
805B:2D9D:DC28:0000:0000:FC57:D4C8:1FFF
32. Cloud Computing
• Put simply is internet computing
• Consists of two ends:
– Front end
– Back end
• Cloud computing today
• Different forms
– Software-as-service
– On demand storage
• Concerns
– Privacy
– Security
33.
34. internet2
• High speed, next generation network led by
educational and research institutes
• Not available to the general public
• A minimum data transfer rate of 155mbps and
a max of 2.5gbps
• More than 3 million users worldwide
• May become the internet of the future
35. Broadband over power line
• High speed internet access over normal power
lines
• Works by bundling RF (radio frequency)
energy with electric current
• Data transfer Speed up to 3mbps
• Could be used in anyplace having electricity
36.
37. Beyond Broadband, Completely
Wireless
• Not more than 5 years ago we were using dial-
up having speeds up to 38.6kbps
• At present 1mbps is the minimum, while
connections up to 8mbps are available
• By 2020 every user will have at least 100mbps
bandwidth
• With the deployment of wimax city wide
wireless internet access would be possible
