Topics / Networks and Data Transmission / Virtual Private Network (VPN)

Virtual Private Network (VPN)

A virtual private network (VPN) is used to securely access a private network (usually a LAN) from a remote location.

VPNs make use of potentially unsafe external (public) communication systems such as the internet.

Once connected to a VPN, the remote computer has secure access to the private network, just as if it was directly connected to the LAN.

Data remains encrypted throughout the entire transmission (this is called tunnelling).

VPN security consists of firewalls, encryption and IP security (IPsec).

Uses of VPNs

  • Network access for travelling employees
  • Network access for teleworking employees
  • Allows staff to access a work network whilst at home
  • Allows LANs within an organisation to connect to each other
  • Individual use for private internet browsing

Advantages of VPNs

  • High level of security of data transmitted over the internet
  • More secure than other remote communication methods
  • Every file is encrypted – so no unauthorised reading of files
  • Cheaper than creating a conventional WAN (no leasing of expensive dedicated telecommunication lines)
  • Adding more clients costs very little
  • Can be configured to work automatically when logging on to a computer
  • External resources are maintained by someone else
  • Enables organisations to communicate over a large area

Drawbacks of VPNs

  • Performance may be outside of the control of the organisation
  • Performance depends on the ISP and so can be variable
  • Packet loss can be higher over a VPN, leading to re-transmission, increasing the time taken to receive documents
  • Some users may have restrictions put on their computers to protect the integrity of the VPN connection (e.g. no third party software, compulsory anti-malware tools)
  • Technical expertise is required to set up and maintain
Topics / Networks and Data Transmission / Virtual Private Network (VPN)