Virtual Private Networks
Provides equivalent of a private packet switched network over public Internet
- Use PVCs (tunnels) that run over the Internet
- Appear to the user as private networks
- Encapsulate the packets sent over these tunnels
- Using special protocols that also encrypt the IP packets they enclose
Provides low cost and flexibility
- Uses Internet; Can be setup quickly
Disadvantages of VPNs:
- Unpredictability of Internet traffic
- Lack of standards for Internet-based VPNs, so that not all vendor equipment and services are compatible