Virtual private networks (VPNs) in mobile environments

Mobile VPNs are used in a setting where an endpoint of the VPN is not fixed to a single IP address, but instead roams across various networks such as data networks from cellular carriers or between multiple Wi-Fi access points.[14] Mobile VPNs have been widely used in public safety, where they give law enforcement officers access to mission-critical applications, such as computer-assisted dispatch and criminal databases, as they travel between different subnets of a mobile network.[15] They are also used in field service management and by healthcare organizations,[16] among other industries.

Increasingly, mobile VPNs are being adopted by mobile professionals and white-collar workers who need reliable connections.[16] They allow users to roam seamlessly across networks and in and out of wireless-coverage areas without losing application sessions or dropping the secure VPN session. A conventional VPN cannot survive such events because the network tunnel is disrupted, causing applications to disconnect, time out,[14] or fail, or even cause the computing device itself to crash.[16]

Instead of logically tying the endpoint of the network tunnel to the physical IP address, each tunnel is bound to a permanently associated IP address at the device. The mobile VPN software handles the necessary network authentication and maintains the network sessions in a manner transparent to the application and the user.[14] The Host Identity Protocol (HIP), under study by the Internet Engineering Task Force, is designed to support mobility of hosts by separating the role of IP addresses for host identification from their locator functionality in an IP network. With HIP a mobile host maintains its logical connections established via the host identity identifier while associating with different IP addresses when roaming between access networks.

Source:
http://en.wikipedia.org/wiki/Virtual_private_network

Google Search:
http://www.google.ch/search?hl=en&q=virtual+private+network&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai=



HOW TO: Set Up A VPN Server On Your iPhone/iPad:

There are a lot of great apps in the app store, but some of them are not accessible to everybody because you can only use them in certain countries ( usually the US ) . One of those apps is Pandora (Pandora). But who said, we need to wait until Pandora is ( if ever ) available worldwide? Here’s what you can do, if you want to use Pandora ( and probably other apps like Vevo and Hulu (Hulu) ) outside the US.

NOTE: the method I’m about to show you here, is totally free. Because it is free, you will get what you paid for. Sometimes the apps work , and sometimes the servers are too busy. Just browse around, maybe you find some better free VPNs , or you can always pay for one, and get much much better results.

So, all you need to do is to configure a VPN server on your iPhone. We’re going to use Hotspot Shield , so lets see how to do that:



1. Turn WiFi OFF and find the VPN settings in Settings> General (general reviews)> Network> VPN> Add VPN Configuration.






2. Select the IPSec tab/pane:





3. Add:

* Select the IPSec tab/pane
* Description: HotspotShield
* Server: 68.68.107.101
* Account: oscor2
* Password: oscor2
* Use Certificate: OFF
* Group Name: hss
* Secret: hss

NOTE: if account and password credentials won’t work, get your own here…

4. You are now done. Save the settings and hit the “HOME” button to quit. Make sure to turn Wi-Fi back “ON”.

5. To activate it on your iPhone, the VPN setting needs to be turned on. From “HOME” menu, go to Settings and click the “On” tab for VPN. Your Status will change to “CONNECTED” and the VPN icon will appear on top in the iPhone Tray when complete. If you cannot connect to the VPN immediately, power down your iPhone, turn it back on, and turn the VPN to “ON”.

If you cannot connect to VPN immediately, power down your iPhone, turn it back on, and turn VPN to “ON” in “Settings”.

6. Enjoy


Source:
http://www.chrisdata.com/2010/08/27/how-to-set-up-a-vpn-server-on-your-iphoneipad-and-use-pandora-outside-the-us/