Main 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 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. VPN services are 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) Explained
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.
Looking for 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.