Data Communication

1. How High-speed Dial-up
Works
Presented by:
Zainab Muneer

2. INTRODUCTION
 Dial-up is often the only choice available
for rural or remote areas where broadband
installations are not prevalent due to low
population and demand.
 The connection speed of dial-up is limited by the
bandwidth of phone lines
 High-speed dial-up connections are five times
faster than traditional dial-up service.
 New technology offers a solution to the slow-
down that doesn't necessitate broadband

3. PROTOCOL
Handshake Protocol
Allows data to be sent to and from your
computer using the Internet
– Modem handshake:
Initialize the internet connection
– Software handshake:
Deals with authenticating the user's access to
the ISP

4. PROTOCOL
High-speed dial-up providers can't do
anything about the modem handshake,
but they can speed up the software
handshake

5. ACCELERATION SERVERS
•
High-speed dial-up allows your machine to
establish a connection with your ISP in a
fraction of the time it takes with standard
dial-up

6. ACCELERATION SERVERS
• By loading special software into a server,
they turn into an acceleration server
• Acceleration servers speed up the dial-up
data transfer using several techniques:
– Compression
– Filtering
– Caching

7. ACCELERATION SERVERS-
Techniques
1. File Compression
Types of file compression:
lossless compression
lossy compression
Acceleration server compresses
different file types
For text files-least 50% compressed
For image files-from 50 % to 90 %
In many other files, including video files, Zip
files and MP3 music files, compression has
already taken place. For example, an MP3 file is

8. ACCELERATION SERVERS-
Techniques
2- Filtering
 High-speed dial-up providers have
bundled a pop-up blocker into the
software
 This pop-up blocker is programmed
to recognize those lines of code that
spell out the ad parameters
 When it sees those tell-tale lines of
code, it rejects the ad's request to be
displayed

9. ACCELERATION SERVERS-
Techniques
3- Caching
Server-side Caching:
 Instead of constantly requesting the
same page, the acceleration server
takes note of which Web pages are
being commonly asked for by all
subscribers
 Then it stores the page in its
memory, and every time another
subscriber asks to see, one of most

10. ACCELERATION SERVERS-
Techniques
3- Caching
Client-side caching
 In high-speed dial-up softwares, the
browser stores the cached pages on
your computer's hard disk
 It looks for elements in those pages
that remain constant (eg homepage,
the logo, the header, the navigation)
 Then only loads what has changed
every time user come to the page

11. CONCLUSION
• High-Speed Dial-up connection uses
the techniques of Accelerator server
to enhance the speed of simple Dial-
up connection
• This technology does not necessitate
broadband
• The key element of high-speed dial-
up Internet is file compression
• Caching and filtering save time by
avoiding unnecessary data