As the enterprises are shifting more towards smart phone based access of company wide resources, the emphasis on establishing a secure connection between the nomadic device (read cell phone or tablet) and the enterprise is increasing. A tablet is mostly seen as an evolution of laptop and hence is expected to run applications like VPN clients anyway. However, a smart phone is more of an extension of the voice communications device and its ability to establish a secure “tunnel” back home requires a bit of digesting.
US National Security Agency (NSA)’s mobility program recently published the Mobility Compatibility Package Guide. This guide talks about various architectural components of the Secure Smartphone VOIP over cellular network. The key requirements presented in this guide is an interesting read.
One of the key challenges would be to manage the applications on the mobile device from provisioning and security viewpoints. That would most likely require a VPN tunnel between the device and the enterprise using the carrier network.
BTW, if you have an android smartphone and if you need to setup a VPN tunnel using that, see this article by Jack Allen.