A network that uses a public telecommunication infrastructure, such as the Internet, to provide remote offices or individual users with secure.

1. Virtual Private Network(VPN)

2. Contents:
▪ Introduction:VPN
▪ Traditional Connectivity
▪ Remote Access Virtual Private Network
▪ Brief Overview of How it Works
▪ Four Critical Functions
▪ Tunneling
▪ Four Protocols used in VPN

3. Contents:
▪ VPNTopology :Type ofVPNs
▪ Remote AccessVPN
▪ Site to siteVPN
▪ VPN Security
▪ VPN : Advantages
▪ VPN : Disadvantages
▪ Applications
▪ Future OfVPN
▪ References

4. Introduction: VPN
▪ Linking of two or more computing devices to share
resources is networking.
▪ Virtual Private Network is a type of private network that
uses public telecommunication, such as the Internet, instead
of leased lines to communicate .

5. Traditional Connectivity

6. Remote Access Virtual Private Network

7. Brief Overview of How it Works
▪ Two connections – one is made to the Internet and the
second is made to the VPN.
▪ Datagrams – contains data, destination and source
information.
▪ Firewalls – VPNs allow authorized users to pass through the
firewalls.
▪ Protocols – protocols create the VPN tunnels.

8. Four Critical Functions
▪ Authentication – validates that the data was sent from the
sender.
▪ Access control – limiting unauthorized users from
accessing the network.
▪ Confidentiality – preventing the data to be read or copied
as the data is being transported.
▪ Data Integrity – ensuring that the data has not been altered

9. Tunneling
▪ A virtual point-to-point connection made through a
public network. It transports encapsulated datagrams.
Encrypted Inner Datagram
Datagram Header Outer Datagram DataArea
Original Datagram
Data Encapsulation
Two types of end points:
 Remote Access
 Site-to-Site

10. Tunneling
▪ MostVPNs rely on tunneling to create a private network
that reaches across the Internet. Essentially, tunneling is
the process of placing an entire packet within another
packet and sending it over a network.
Tunneling requires three different protocols:
▪ Passenger protocol -The original data (IPX, IP) being
carried
▪ Encapsulating protocol -The protocol (GRE, IPSec, L2F,
PPTP, L2TP) that is wrapped around the original data
▪ Carrier protocol -The protocol used by the network that
the information is traveling over

11. Four Protocols used in VPN
▪ PPTP -- Point-to-Point Tunneling Protocol
▪ L2TP -- Layer 2 Tunneling Protocol
▪ IPsec -- Internet Protocol Security
▪ SOCKS – is not used as much as the ones above

12. VPN Topology : Type of VPNs
▪ Remote Access VPN
▪ Site-to-Site VPN
▪ Intranet VPN
▪ Extranet VPN

13. Remote AccessVPN
▪ Remote-access, called as virtual private dial-up network
(VPDN)
▪ LAN connection used by a company that has employees
who need to connect to the private network from various
remote locations.
▪ Remote-access VPNs permit secure encrypted
▪ connections between a company's private network.

15. Site-to-Site VPN
▪ Intranet-based - If a company has one or more remote locations
that they wish to join in a single private network, they can
create an intranet VPN to connect LAN to LAN.
▪ Extranet-based - When a company has a close relationship with
another company (for example, a partner, supplier or
customer), they can build an extranet VPN that connects LAN
to LAN, and that allows all of the various companies to work
in a shared environment.

18. VPN Security
▪ A well-designed VPN uses several methods for keeping your
connection and data secure:
▪ Firewalls
▪ Encryption
▪ IPSec
▪ You can set firewalls to restrict the number of open ports, what type of
packets are passed through and which protocols are allowed through.

19. VPN : Advantages
▪ Cost Savings .
▪ Extend geographic connectivity.
▪ Improve security
▪ Provide broadband networking compatibility
▪ Improve productivity
▪ Reliable

20. VPN : Disadvantages
▪ VPNs require an in-depth understanding of public network security
▪ VPN require more tools.

21. Applications
▪ Healthcare: enables the transferring of confidential patient
information within the medical facilities & health care
provider
▪ Manufacturing: allow suppliers to view inventory & allow
clients to purchase online safely
▪ Retail: able to securely transfer sales data or customer info
between stores & the headquarters
▪ Banking/Financial: enables account information to be
transferred safely within departments & branches
▪ General Business: communication between remote
employees can be securely exchanged

22. Future OfVPN
▪ VPNs are continually being enhanced.
Example: Equant NV
▪ As the VPN market becomes larger, more applications
will be created along with more VPN providers and
new VPN types.
▪ Networks are expected to converge to create an
integrated VPN
▪ Improved protocols are expected, which will also
improve VPNs.

23. Future ofVPN: Companies withVPN

24. References:
▪ http://vpn.shmoo.com/
▪ http://www.uwsp.edu/it/vpn/
▪ http://info.lib.uh.edu/services/vpn.html
▪ http://www.cites.uiuc.edu/vpn/
▪ http://www.positivenetworks.net/images/client-
uploads/jumppage2.htm
All reference links have been checked so far and have been found running on 10-08-2013

25. References
▪ <www.csun.edu/~vcact00f/311/termProjects/700class/VPN.ppt>
▪ Mitchell, Bradley. "VPN Tutorial." About.Com. 2007. 8 Mar. 2007
<http://compnetworking.about.com/od/vpn/l/aa010701a.htm>.
▪ Tyson, Jeff. "How Virtual Private Networks Work." How Stuff Works.
6 Mar. 2007 <http://computer.howstuffworks.com/vpn.htm>.
▪ "Virtual Private Network." Wikipedia: the Free Encyclopedia. 6 Mar.
2007. 9 Mar. 2007 <http://en.wikipedia.org/wiki/Vpn>.
All reference links have been checked so far and have been found running on 10-08-2013