Virtual Private Networks (VPNs)

What is a VPN?

Connecting into the secure environment of a business network used to involve a dial up session to negotiate your way to the desired data through a remote access server - today much of the complexity has been by-passed with the widespread use of virtual private networking (VPN).

Rather than the cost of long distance calls and the need to support a bank of modems and dial-in lines users can now gain the same access to corporate data via a secure internet connection as they would sitting at a desk inside the business.

This has opened the way for global access using dial-up, DSL (digital subscriber line), cable modems or ISDN (integrated services digital network) through a local internet service provider.

A VPN creates a secure tunnel across the shared or public network to act as part of the corporate wide area network (WAN). The link is a secure virtual link between the client and host computers which encapsulates or wraps the data being exchanged with a header that provides routing information allowing it to reach its destination. Through a VPN workers can connect to central resources and communicate with each other.

VPNs typically employ a high level of encryption and a firewall with up to three layers of security. A virtual point-to-point session is enabled after password and other authentication is verified by the company firewall and router and encryption applied.

  • Encryption transforms data into a form that can be read only by authorised personnel.  Encrypting all IP (Internet Protocol) packets when sending them over the public network between VPN boxes is known as creating a “tunnel”.
  • Authentication verifies the identity of each users and the level of access they are allowed to have into the networked information systems.
  • Running the transmission through a firewall adds protection from intrusion and abuse.  Through checking the content and origin of IP packets, firewalls can be used to give more secure access to the Internet, as well as separating a company’s public web servers from it’s corporate network.

What issues need consideration

VPNs are typically used by remote branch offices and remote employees operating away from the central office or those needing to connect into certain information as part of an extended relationship, including consultants and supply chain partners.

A VPN may be an outsourced solution installed on behalf of an organisation by a third party or installed internally using routers and firewalls and managed by the IT department as an extension of its LAN and WAN technology.

Organisations must already have an efficient intranet and extranet operating and know what information can be made available to outsiders without compromising security and competitiveness.

This requires tight network management and security policies to be implemented and decision on what level of access remote users and those outside the organisation will have to corporate systems.

Special protocols have had to be developed to ensure the VPN is the safest and most secure means of communication possible.  Microsoft’s Point to Point Tunnelling Protocol (PPTP) was the first developed for the Windows NT environment now the IP Security (IPSec) protocol has become an industry standard protocol, often used alongside Layer 2 Tunnelling Protocol (L2TP) to help out with IP addressing management on VPN clients.

Who should consider installing a VPN?

Companies with mobile workers, telecommuters, branch offices, partners, suppliers and customers and those who have already established intranets and extranets can quickly benefit from the use of a VPN.

In the past dial up lines for remote workers added complications and potential areas for security breach within an organisation and dedicated digital data services or leased lines were expensive and only operated from point to point.

This means corporates can now get the same benefits of having a private network without the expensive infrastructure costs. To users and network administrators, geographically distant site  are treated as though they were directly connected.

With an Internet solution, a few Internet connections through Internet service providers (ISPs) and a VPN server an organisation can serve the remote networking needs of hundreds or thousands of remote clients and branch offices.

  • Mobile workers, telecommuters, remote offices and members of your supply chain can have affordable, efficient, managed links with your in-house systems
  • Companies sharing confidential information with remote users can have a secure connection.
  • Companies whose business could be harmed if a competitor intercepted the transmissions can be confident of private and safe information exchange.

Remote users can access only the agreed levels of information.

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