Today, there a variety of mobile devices that are designed to keep a user updated with current information. These include personal digital assistants, wireless phones, email devices, and the like. Mobile devices are now capable of connecting to the Internet thorough various means and thus exchange information over the Internet. But, in addition to the Internet, these mobile devices would also like to send and receive information on the user's corporate network. This may include emails, attachments to emails, web page content, and the like.
Many corporations provide access to their corporate network from the Internet through a VPN (Virtual Private Network). VPN connections are used to establish a secure tunnel from a public Internet connection into a private/corporate network. Most corporations enable such secure connections into their private networks from a public Internet connection so a mobile device with a connection to the Internet can use a VPN connection to access the corporate network. It is often cumbersome, however, to connect to a user's corporate network through a VPN from a mobile device.
Most cellular networks typically only provide ways for mobile devices to connect to the Internet either through slow circuit-switched RAS connections or high-speed GPRS/1×RTT data connections.