1. Presented by-
Mr.jayant N. Rajurkar
M.Tech (CSE)

2. Table of content
1. Introduction
2. Literature Review
3. Operation
4. Security
5. Advantages
6. Limitations
7. Conclusion
8. References

3. Introduction
•The ability to access and operate one computer from another
computer remotely in today’s world is an essential and can be
achieved by the help of Network Computing Technology
(VNC).
•VNC enables the desktop display of one computer to be
remotely viewed and controlled over a network connection
•To use VNC, need a network TCP/IP connection, a
VNCserver and a VNCviewer to connect to the machine
running the VNCserver

4.  Giving users access to resources located anywhere in
network.
 Allows a single desktop to be accessed from several
places.
 VNC also have application in Mobile computing
 implement a prototype system for mobile VNC,
and several works are done for improving screen
update rate.

5. Literature Review
Sr
No
.
Paper Title Author Transaction Remark
1. Comprehensive review
and Selection criteria
for Virtual Network
Computing
Technology
Marzieh
Yazdanipour,
Davood
Mahmoudi
IEEE,2013 In this paper VNC
technology is defined
and Cross platform
desktop sharing is
explained with an
example
2. Implementation and
Evaluation
of Fast Mobile VNC
Systems
Ha-Young
Ko, Jae-
Hyeok Lee,
Jong-Ok
Kim,
IEEE,2012 In this paper, they
implemented a prototype
system for mobile VNC,
and reported practical
performance evaluations.
3. Virtual Screen for
Cloud Thin Clients
Shruti
Kanetkar,
Hamid
Shahnasser
IEEE,2012 The concept of virtual
screen is definitely
useful as the user is able
to access a Cross-
platform terminal

6. Literature Review(Contd…)
Sr
No
Paper Title Author Transaction Remark
4. Virtual
Educational
System and
Communication
Zona O.
Kostic,
Aleksandar
D.
Jevremovic
IEEE,2011 Virtual Educational System
has been developed as a
distance education system
which enables fully
integrated real and virtual
communication
5. Extending VNC
for Effective
Collaboration
Tae-Ho
Lee, Hong-
Chang Lee
IEEE,2011 presents an extension of
VNC for synchronous
collaboration with various
access policies. provide
three kinds of access
authorities: administrator,
worker, and spectator
6. Improving the
Performance of
VNC for High-
Resolution
Display Walls
Yong Liu,
Otto J.
Anshus
IEEE,2010 Paper desribes the transfer
of pixels at high
bandwidth because of not
enough network bandwidth
of VNC in network

7. Operation
 need is a network TCP/IP connection, a
VNC server, and VNC viewer for
connecting to the computer that is running
the server
 The VNC protocol remote frame buffer
(RFB) protocol is used to remotely control
another computer
 VNC protocol allows the client and server to
negotiate which encoding will be used

9. Operation
 Simplest encoding - Raw Encoding
 Encoding works :
 Pixel data is sent in left-to-right scan line order
 Only transfer rectangles that change
 Supported by all clients and servers

10. Operation
 Default uses TCP ports 5900 through 5906
Each port to a separate screen (:0 to :6)
Other ports can be used
 Both client and server configured accordingly
Some O.S only support a single VNC session
at a time
 E.g. Windows XP

11. Operation
 Server does not necessarily have a physical
display (Unix/ VNC server)
- Xvnc , based on a standard X server
- Two servers in one
applications an X server
to remote VNC users as VNC server
 Unix/Linux X11 Multiple VNC sessions

12. Operation
 VNC is a cross-platform remote desktop
system
- Apple Remote Desktop for Mac OS X
 From Linux, TightVNC will connect to an OS X
session
 VNC is a platform independent system

13. Security
 By default, VNC is not a secure protocol.
- Passwords are not sent in plain-text (as in
telnet)
 It is recommended that a password of at least 8
characters be used.
- There is also an 8-character limit on some
versions of VNC;
 If a password is sent exceeding 8 characters
Excess characters are removed
Truncated string is compared to the
password.

14. Security
 VNC may be tunneled over an SSH or VPN
connection
 Adds an extra security layer with stronger
encryption
 SSH clients are available for all major platforms
 SSH tunnels can be created from
 UNIX clients
 Microsoft Windows clients
 Macintosh clients many others

15. Security
 UltraVNC supports the use of an open-source
encryption plugin
◦ Encrypts the entire VNC session
◦ Including password authentication and data transfer
 Allows authentication to be performed based on
Active Directory user accounts
 RealVNC offers high-strength encryption

16. Advantages
 Less Costly
 Greater efficiency & time saving
 Efficient use of network
 Platform Independent

17. Limitations
 The remote machine needs to have VNC server
activated. Otherwise desktop share is not
possible.
 VNC is not encrypted. So, we need to add SSH
for ensuring secure connection.
 Compression is not efficient. Hence, it affects
the working capability of remote user.

18. Conclusion
 The accelerating diffusion of digital
media and wireless network,together
with the increased naturalization of
computer mediated communication.
 Virtual Educational System has been
developed as a distance education
system which enables fully integrated
real and virtual Learning.

19. References
 Marzieh Yazdanipour, Afsaneh Yazdanipour, Amin Mehdipour,” Comprehensive review
and Selection criteria for Virtual Network Computing Technology”,IEEE,2013.
 Ha-Young Ko, Jae-Hyeok Lee, Jong-Ok Kim,” Implementation and Evaluation of Fast
Mobile VNC Systems”,IEEE,1211-18,2012
 T. Richardson, “The RFB Protocol,” Tech. rep., RealVNC Ltd, published, 2012.
 “The RFB Protocol”, Tristan Richardson RealVNC Ltd, (formerly of Olivetti Research
Ltd / AT&T Labs Cambridge), Version 3.8, Last updated 26 November 2011
 K. Kaplinsky, “VNC tight encoder-data compression for VNC,” The 7th International
Scientific and Practical conference of Students, Post- graduates and Young
Scientists, pp. 155–157,2011
 Zona O. Kostic, Aleksandar D. Jevremovic1 Dragan S. Markovic, Ranko M. Popovic,”
Virtual Educational System and Communication” 373-76 , Serbia, Nis, October 5 -
8, 2011.

20. Thank You…