WHY USE VPN?

The VPN service is designed to allow CalNetID authenticated users to connect to the network from outside of internal lan, as if they were on campus, and encrypts the information sent to the network.
When you use a VPN connection, it appears to systems on campus that you are also on campus - you will have a UCB IP address instead of the one you have at home (through your dsl/dialup service's ISP). The VPN offers a way for authorized users to 'tunnel' in to the campus network, to access UCB resources normally not available from home machines, bypassing any port blocking at the campus border. Note: traffic is encrypted from your workstation through the network to the VPN concentrator hardware at UCB, but at that point the traffic is un-encrypted and sent out over the campus network. (If you are using software like ssh, your traffic on the campus network remains encrypted.)
If you use a VPN connection from an *on-campus* location, the encrypted part of your traffic is still between your workstation and the VPN concentrator.

You may want to use a VPN connection if:

* you need access to restricted services.
* you use network protocols like NetBIOS to a host or service on campus. (some ports are blocked at the campus border for security reasons.)
* you mount a Windows disk share from your work computer on your home computer.

You don't need to use a VPN connection if you check your email via IMAP or POP. Downsides to using a VPN include:

* slows down your connection
* uses resources others could be using
* adds an extra step to connect to UCB