What Does VPN Mean?

VPN stands for ‘Virtual Private Network’ and refers to the secure way of connecting to a Local Area Network using encryption through the Internet or another type of public network.
The primary purpose of VPNs is to allow remote workers or companies with remote offices to share private data and network resources with a central location, head office or headquarters. VPN uses authentication to prevent unauthorised users from gaining access to the private data in the event that they attempt to intercept it. It can be used to send any kind of network traffic securely.
Virtual Private Networks reduce network costs for companies and individuals because they avoid the need for physical leased lines to connect remote offices or users to a private internal network. With a VPN, users are able to transfer and exchange their private data safely and securely without the need for such physical lines. Leased line was previously the most commonly used method of connecting computers at multiple locations, but in recent years more and more businesses have replaced these leased lines with new technologies to allow them to adopt a VPN instead. VPNs are vital where employees use a company’s own private internal network on a day-to-day basis in their work. Adding a VPN allows a business to allow its employees access to its entire intranet from a remote location.
The main motivation for companies to switch to using a VPN is cost, reliability and speed. The fast development of Internet Service Providers means that businesses can create a VPN using their Internet connection without sacrificing the speed and reliability of the connection, while at the same time maintaining the relatively low cost they pay for Internet access. Leased lines, on the other hand, are often expensive with rising costs over longer distances.

An internet is private to one group (sometimes called isolated) if none of the facilities or load is accessible to other groups. Typical implementation involves using leased lines to interconnect routers at various sites of the group. The global Internet is public because facilities are shared among all subscribers.

Hybrid architecture is one, which allows some load to go over the private connections and also allows contact with global internet.Private networks are really expensive to build but on the other hand, Public Internet access is inexpensive. The goal of VPN is to combine the safety of private network with low cost of global internet.

VPN connects all the sites to global internet by providing protection to the data passing through the global internet using encryption or IP-in-IP tunnelling. For example, consider a company having a head office in London and wants to open a branch in Pakistan. It has a private network in London office and wants to have another private network in Pakistan. It's not practical to have a leased line between the two networks for connection. For the connection we can use VPN. Through VPN both the networks will be connected and no one will be able to interpret the contents because either the data sent will be encrypted or will be IP-in-IP tunnelled.

VPN is used by private companies to communicate over the public network

VPN traffic can be carried by two ways:

Public networking infrastructure like internet.

Service provider's private network that might be a legal agreement between VPN customer and VPN service provider.

A VPN can send data like audio,video, or combination of these between two points through encryption that enhances the privacy of data.

VPN can be cost effective and secure for the organizations to provide an access to their users to the corporate networks like internet or the private networks.
VPN are cost effective they have two parts:

INSIDE network(physical administration is provided to protect transmission)
OUTSIDE network(less trustworthy like internet)

VPN has the following protocols:
IP sec(IP SECURITY)
SST/TLS
Open VPN
Point to point tunnelling protocol(PPTP)
L2TP(layer to tunnelling protocol)
L2PV3(layer 2 tunnelling protocol version 3)
VPN quarantine
MPVPN(multi path virtual private network)


BENEFITS OF VPN

Data send across the internet is not secure. It can be effected by unauthorized users. So you can make it secure through virtual private connection.

VPN connection uses encryption and tunnelling techniques to transfer data securely on the internet.

Makes you save the money by avoiding long distance calls and just what you have to do is to use the public internet.

A Private network is the network build up from company's computer, devices and leased line. Virtual Private Networks are the networks that enable the organization to build up private network over public networks. Main features of Virtual Private networks are security, reliability, scalability, network management etc. Virtual networks are called Virtual because those are merely illusions just like virtual circuits.

There are three main key features required to ensure security on Virtual Private Networks; encryption (encoding data on transmission), Encapsulation (encrypted package is covered inside an IP packet with a new header and deliver to other device) and authentication (verification of user identity). Virtual Private Network use several Methods to keep connection and data secure. Firewall, encryption, IPSec and AAA are the most commonly use methods, Virtual Private Networks has four Protocols; L2F, PPTP, L2TP and IPSec. L2F, PPTP, L2TP are Layer 2 Protocols and IPSec is layer 3 protocol. IPSec is the most advance protocol of Virtual Private Network.

The QoS for IP Virtual Private Network is measured by 3 parameters; jitter (Change in time between packets), latency (Delay) and packet delivery. Virtual Private Network is used when more locations, longer Distance, less Bandwidth/Site and Qos less critical.

A Virtual Private Network is a secure dedicated network used for the transmission of data and information across distances. It provides security to the users. The key feature of the Virtual Private Network is that it uses encryption and tunneling. The Virtual Private Network provides security of data on the internet and reliability of data communication over the internet. It is useful for the end user. The VPN has two parts that are used for security - one is hardware and the other is software. You can connect your network through VPN securely by using hardware and software.

The virtual private network provides security to the users and it is very reliable for data flow. It uses the internet to communicate with other people. It provides safe accessibility to the networks of the organization. The usage of the virtual private network is commonly used because of its low cost and it is very popular in businesses. It uses the approach of a dedicated line for transferring data. It uses security protocols over public networks to provide security to the users. The virtual private network not only uses encryption but also decryption on the data. The protocol which is used by the virtual private network is L2PT.