VPN – virtual private network
A virtual private network (VPN) is a network that is constructed using public wires — usually the Internet — to connect to a private network, such as a company's internal network. There are a number of systems that enable you to create networks using the Internet as the medium for transporting data. A VPN secures the private network, using encryption and other security mechanisms to ensure that only authorized users can access the network and that the data cannot be intercepted.
VPNs Offer Privacy and Security
A VPN is designed to provides a secure, encrypted tunnel in which to transmit the data between the remote user and the company network. The information transmitted between the two locations via the encrypted tunnel cannot be read by anyone else because the system contains several elements to secure both the company's private network and the outside network through which the remote user connects through.
The first step to security is usually a firewall between the client and the host server, requiring the remote user to establish an authenticated connection with the firewall. Encryption is also an important component of a secure VPN. Encryption works by having all data sent from one computer encrypted in such a way that only the computer it is sending to can decrypt the data.
VPN Network Protocols
There are three main network protocols for use with VPN tunnels. These protocols are generally incompatible with each other. They include the following:
A set of protocols developed by the IETF to support secure exchange of packets at the IP layer. IPsec has been deployed widely to implement VPNs. IPsec supports two encryption modes: Transport and Tunnel.
The Point-to-Point Tunneling Protocol is a technology for creating VPNs, developed jointly by Microsoft, U.S. Robotics and several remote access vendor companies, known collectively as the PPTP Forum.
Layer Two (2) Tunneling Protocol is an extension to the PPP protocol that enables ISPs to operate Virtual Private Networks (VPNs).
Consumer Versus Corporate VPN Services
Consumers use a private VPN service, also known as a VPN tunnel, to protect their online activity and identity. By using an anonymous VPN service, a user's Internet traffic and data remain encrypted, which prevents eavesdroppers from sniffing Internet activity. A VPN service is especially useful when accessing public Wi-Fi hotspots because the public wireless services might not be secure. In addition to public Wi-Fi security, a private VPN service also provides consumers with uncensored Internet access and can help prevent data theft and unblock websites.
Companies and organizations will typically use a VPN to communicate confidentially over a public network and to send voice, video or data. It is also an excellent option for remote workers and organizations with global offices and partners to share data in a private manner.
Virtual private dial-up network (VPDN)
One of the most common types of VPNs used by businesses is called a virtual private dial-up network (VPDN). A VPDN is a user-to-LAN connection, where remote users need to connect to the company LAN. Another type of VPN is commonly called a site-to-site VPN. Here the company would invest in dedicated hardware to connect multiple sites to their LAN though a public network, usually the Internet.
Free VPN Services
Free VPN usually refers to services and tools that let you browse the Web securely and anonymously. The tools are typically available for desktop and mobile Web browsing. Read Webopedia's 5 Free VPN Services article to learn more.
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