Virtual Private Networks

Is it true?



Is it possible to access a Web page from anywhere in the world? You
will now say, ‘YES’. Now another question. Is it possible to access

resources in the your network from anywhere in the world? You are in a foreign

country and you need some information that you have in your network far

here in India. How nice it is if you can log in just like into the Web and

access it from there. It is possible with the Virtual Private Networks that is gradually

gaining roots.

What is VPN?



A Virtual Private Network (VPN) in simple terms is the use of a public
network for private use. In other words, it is a network that uses a

public network service (Internet) as the backbone of its Wide Area

Network. Pay the service provider (ISP) and your headache is over. A VPN

digs out a way, rather a private passage for the company network through

the Internet.

Problems



Of course VPNs are appealing at the very outset. However there are very evident problems that
might prevent one from opting a VPN. Here are a few of them.

- Security



Your network has crucial
data in it. Naturally the doubt would be whether the data is safe and

secure, once it is accessed through a VPN. Many security protocols are

emerging, which might prove all the existing fears to be wrong.

- Bandwidth problems



We spend so much of time
idle in front of the system for a web page to download. There is not

enough bandwidth. Then how is it that you can be assured that you can

access the required resources when and where you need? Service providers

are trying to find out ways to do this. Maybe they can strictly manage the

available bandwidth and prioritize the usage.

Reliability of the

Internet



Is the Internet reliable?
Not always. While the Internet backbone is pretty robust, ISP gateways do

fail occasionally and these can make your VPN a better dream than a

reality.

VPN tunneling technology



How is the data carried
from one point to another through the Internet? It uses the tunneling

technology.

Tunneling, also known as

encapsulation enables a network to send its data via another network’s

connection. Here a network protocol is encapsulated within packets carried

by a second network.

VPNs can send data in two

ways.




Encapsulation




It is simply bundling one protocol into
another. As you all know, Internet uses TCP/IP. So the VPN data is

encapsulated to TCP/IP. However this method does not guarantee proper

security of your data. So it is not widely used.

Encrypted encapsulation



Before being sent, the
packets are encrypted so that the data is unreadable to outsiders. These

packets now travel through the Internet to the destination. Once it

reaches the destination, the packets are changed to their original format.

Only those who have authorization to contact the server can retrieve the

data.

Models of tunneling



There are two models, of
tunneling

- Client initiated



To connect to the VPN
server, here the client has to dial to the local ISP using the respective

VPN client. Depending upon the tunneling protocol being used, the client

will have to go through an authentication process.

- Client-transparent

tunneling



Here the tunnel-enabled
server (the server dedicated for VPN connectivity that the ISP has) has

dedicated connectivity with VPN servers of various companies. When needed,

the clients connect to the local ISP and access this server. After

authentication, the clients are directed to their respective VPN servers.

They have to cross the company’s security gateway to login.

Tunneling protocols



The major fear that holds
back network managers from going in for VPN would be the security factor.

The prominent players in the field of VPN know this and are coming out

with new and new tunneling protocols, which they say will safeguard data.

Among the prominent ones are the Point to Point Tunneling Protocol (PPTP)

developed by Microsoft and the Layer 2 Forwarding (L2F) developed by Cisco.

There is the Internet Protocol Security(IPSec) which provides secure

communications transparency. It is a standard chosen by the Internet

Engineering Task Force(IETF). Microsoft and Cisco with IETF are in an

attempt to merge this protocols into a standard called Layer 2 Tunneling

Protocol(L2P2).

Virtual Private Networks



Access your company's network resources

from anywhere in the world

VPNs in easy steps





Use NT to connect your company’s multi-location networks over the

Internet

VPN source page





A one-stop source for VPN Information. An educational resource for anyone

interested in virtual private networks.

What is Virtual Private

Networking



What can you do if you just want to give

company insiders and a few select business partners and customers easy and

relatively secure remote access to company data via the Internet? You can

set up a virtual private network.

A virtual private affair





Virtual private networks offer some serious savings -- if you know the

secret.