VPN = Virtual Private Network

A network within a network. A VPN allows the creation of a virtual network that can use other networks (e.g. the public internet) for transport. VPNs often encrypt any data they send over the transport network.

Commonly used VPN implementations:

1. IPSec/OpenSwan: Part of IPv6, difficult to setup and particularly complicated in NATted environments
2. OpenVPN: Easy to set up, uses SSL
3. PPTP: Microsoft protocol that comes with known security flaws

See also

• Wikipedia - VPN Article
• VOIP and VPN
• Asterisk encryption