Virtual Private Network | Part 1

Virtual Private Network | Part 1

Virtual Private Network

A Virtual Private Network or VPN is a private telecommunications network was established between subjects using a system of public broadcasting and shared such as the Internet. The purpose of VPN is to give companies the same opportunity to rent private lines at a lower cost by using shared public networks.

VPN Features

The networks use VPN connections that require authentication to ensure that only authorized users can access, to ensure the security data sent across the Internet will not be intercepted or used by others not authorized, they use encryption.

VPNs secure protocols shall therefore ensure that encrypt the traffic transiting the VPN. In addition to encryption, a secure VPN to provide its protocols of the mechanisms that prevent security breaches such as identity theft or alteration of digital messages.

The term VPN is a generic term and not a brand. In particular, there is no body that regulates the designation of a product as a VPN, so that individual producers can use at will.

However, there are several independent bodies, widely recognized certifying interoperability and security of computer systems, such as ICSA Labs. A device or software, that includes the trademark of ICSA Labs IPSec VPN, has certainly undergone a series of objective tests and replicable, which ensures compatibility with all other implementations certified and an adequate level of security. It is now generally accepted that a properly designed VPN has a degree of security comparable to that of a dedicated network. Using a VPN, using an Internet connection, for example, is able to connect to the private network from outside your office.

Generally, a VPN consists of two parts: one inside the network, and therefore protected, which preserves the transmission, and a less reliable and secure which is outside the private network, such as via the Internet. The VPN is usually a firewall between the computer of the employee or a customer and the terminal or network server. The employee, for example, when establishing the connection with the firewall, it must authenticate the data that wants to transmit, via an authentication service inside.

An authenticated user may be provided with special privileges to access resources that are generally not accessible to all users. Most programs require that all the client’s IP VPN traffic will pass through a “tunnel” between the virtual networks using the Internet as a means of connection. From the point of view this means that while the VPN connection is active, all access outside the secure network must pass through the same firewall as if the user were physically connected within the secure network. This reduces the risk that external users can access the private network of the company.

The security of the VPN connection is crucial, because the network on which the other computers are working may not be secure, or only partially. The VPN must guarantee a level of security that protects the computers of employees who are working simultaneously on the same network, among which one could be infected with a virus, worm or Trojan.

Types of VPN


Trusted VPN

Ensuring that the network is trusted VPN provides security that no unauthorized third party may use the circuit of the customer. This implies that the customer has its own IP address and its own security policy.

The circuit travels through one or more “switches” of communication that can be compromised by those who want to disrupt network traffic. The customer of a VPN is therefore expected that the provider (ISP) maintains the integrity of the VPN circuit to prevent intruders.

Companies that use a Trusted VPN want to be sure that their data moves through a series of routes that have specific properties and which are controlled by an ISP (Internet Service Provider). The customer then has confidence that the paths through which these data are kept safe move according to the criteria of a previous agreement, although generally the customer does not know what are the paths used by the provider of Trusted VPN.

Trusted VPN Requirements

No one outside of the provider of Trusted VPN can affect the creation or modification of the VPN route. No one outside of the trust can change any part of the VPN. No one outside of the provider of Trusted VPN can modify the data input or those removed from the path of the VPN.

The data traveling in different pathways that are shared by multiple customers of the supplier, the path must be specified by the VPN and no one except the trusted provider can edit the various data. The location and the address used in a trusted VPN must be established before the VPN is created.

The customer must know what they expect from the supplier, so that both can plan and create the network for which they are collaborating.

Technologies used by the Trusted VPN

The technologies used are divided into Layer 2 and Layer 3;

Layer 2

  • Circuits ATM (Asynchronous Transfer Mode)
  • Transmission circuits
  • Layer 2 transport over MPLS

Layer 3

  • MPLS with limited distribution information of the route through BGP (Border Gateway Protocol).



Santosh is an experienced content writer with good search engine optimisation skills. Santosh works with our marketing department in the creation of articles and how-to guides for our company blog and knowledgebase.


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