Mobile VPN also supports Network Address Translation-Traversal (NAT-T) and IKEv2 Mobility and Multi-homing, to negotiate fast reconnections if the wireless link breaks. Users can pick up in an application where they left off, says Traynor.

The MDM server draws on and works with the capabilities of an array of Microsoft server capabilities. It integrates fully with Active Directory, for example, and supplements the mobile messaging management and security features in Exchange Server 2007, and the inventory management and configuration capabilities of System Center Configuration Manager 2007.

It's the kind of approach that Microsoft-based enterprises are looking for, says Ken Dulaney, vice president at market research firm Gartner. Mobile VPN "reduces network overhead and proxies IP addresses to reduce the battery consumption caused by independent applications that [constantly] ping the network to ensure their connection is being maintained," he says.

One key rival in this space is Research In Motion (RIM), with its BlackBerry Enterprise Server. But RIM and Microsoft focus mainly on managing their respective software platforms and the handsets running them, says Benjamin Gray, an analyst with Forrester Research.

Enterprises that use other platforms, such as Symbian, or have a mix, can turn to Nokia's Intellisync Mobile Suite, HP's Enterprise Mobility Suite, Good Technology's Mobile Messaging (now part of Motorola), Motorola's own MotoPro Mobility Suite, Sybase iAnywhere's Afaria Mobile Device Management, and Wavelink's Avalance Mobility Center, among others, according to Gray.

The new mobile operator services being built around MDM are due out later this year from various cellular carriers, including in the US, AT&T and Verizon Wireless. According to Traynor, the implementations of these "Mobile Services Plans" will simplify mobile deployments by giving enterprises a single locus for MDM client licensing, device purchase, support and maintenance, and a guarantee of a high-quality network connection for mobile users.

Again, Microsoft is moving into a crowded field. "Many carriers and infrastructure outsourcers offer handheld management services that are powered by mobile device management vendors like Nokia or Mformation," says Forrester's Gray.