Over the past year, many companies have deployed Microsoft Mobile Information Server 2002, Microsoft's latest version of its Wireless Application Gateway (WAG). Although Mobile Information Server has some great features, it also has some disadvantages. As a result, if you're thinking about implementing a WAG, you might want to consider some other vendors' products as well.

Do You Need a WAG?
WAG is a common term for the piece of enterprise infrastructure that acts as a gateway for mobile and wireless devices to access an enterprise's data sources and resources. WAGs have been on the market for quite some time. Typically, WAGs are installed on standalone servers that reside either in or behind a corporate demilitarized zone (DMZ). WAGs aren't required to support enterprise mobile and wireless applications, but WAGs' features often make their deployment a good architectural decision. Key reasons to implement a WAG include the following:

  • Multiple-device support—Most companies don't use a standard type of mobile or wireless device or a standard OS. With WAGs, companies can support multiple devices and OSs.
  • Multiple data-source support—Most WAGs natively support access to personal information manager (PIM) functionality, such as access to email, calendar entries, and contacts on enterprise email servers. Some WAGs also support access to custom data sources and various file types.
  • Remote device management—Remote device management is essential when you must support numerous mobile users who are remote or constantly on the go. Many WAGs feature remote device-management functionality. The functionality can be simple (e.g., remote device configuration, remote backup and restore) or advanced (e.g., remote software installations, remote device recovery).
  • Optimized wireless connectivity—Wireless network coverage, bandwidth, and reliability can vary widely. WAGs often include advanced connection-optimization and data-compression mechanisms that enhance the available bandwidth and reliability of wireless connections.
  • Enhanced security—Security is an important consideration when you implement mobile and wireless solutions in an enterprise. When WAGs reside in or behind the DMZ, in many cases, wireless and mobile devices can't directly connect to the corporate network. In addition, most WAGs feature enhanced authentication to prevent unauthorized access and an encryption mechanism that encrypts all data transmitted to and from the mobile device.
  • Multiple-connection support—When PDAs first came out, you could synchronize data only through a cradle, which meant that you needed a PC to transfer data to and from the PDA. With the introduction of WAGs came more connectivity options. Nowadays, most WAGs let you synchronize data in a variety of ways, including cradles, wireless WAN (WWAN), wireless LAN (WLAN), and Bluetooth. These connectivity options make users truly mobile yet still connected.
  • Industry-standard support—Most of the leading WAGs support appropriate industry standards, including XML, Simple Object Access Protocol (SOAP), SyncML, and Wireless Application Protocol (WAP). Support for industry standards is important if you want to build custom line of business (LOB) applications (i.e., applications that are vital to running an enterprise) on top of the WAG platform and integrate the WAG platform successfully into enterprise infrastructure.

Useful Server Features
Mobile Information Server has several key features, including Microsoft Outlook Mobile Access, Microsoft Server ActiveSync, Intranet Browse functionality, and notification functionality. Outlook Mobile Access is a mobile version of Outlook Web Access (OWA) that supports WAP and is accessible through microbrowser devices. Outlook Mobile Access provides realtime access to Microsoft Exchange Server email, calendar entries, tasks, personal contacts, and the Global Address List (GAL).

Server ActiveSync lets users synchronize email, calendar entries, and contacts over any connection (e.g., WWAN, WLAN, cradle, dial-up). Server ActiveSync synchronizes the data from Exchange to the wireless or mobile device, which means that even when a connection isn't available, you can use the device's features and access your data. The supported devices are Pocket PC 2003 and Pocket PC 2002 and the new Windows Powered Smartphones, which are scheduled for release later this year. Server ActiveSync can transfer data only through a Secure Sockets Layer (SSL) connection, so all data is encrypted end-to-end from the device to Mobile Information Server. Mobile Information Server truncates all messages and downloads only the first 0.5KB of each message, which makes Server ActiveSync efficient over lower bandwidth connections. You can customize the truncation to change how much of each message is downloaded.

Intranet Browse uses a reverse-proxy type of functionality to let Internet-capable microbrowser devices access microbrowser applications hosted within the corporate network. The notification functionality lets you send short messages to mobile and wireless devices that support Short Message Service (SMS) or SMTP messages. Thus, users can receive notifications about calendar changes, important email, and so forth. In addition, you can use COM or SOAP APIs to create custom applications that leverage Mobile Information Server's notification infrastructure.

Disadvantages
Mobile Information Server is a solid product that integrates well with Exchange and other Microsoft products. I use Server ActiveSync to synchronize my Exchange email, calendar, and contacts. However, using Mobile Information Server has a few disadvantages.

Because Mobile Information Server supports only Pocket PCs and simple WAP-enabled devices, Mobile Information Server is a point solution. Support for other devices requires additional infrastructure.

To use all of Mobile Information Server's features, you must use Active Directory (AD) updates. In addition, Server ActiveSync and most other Exchange-related features in Mobile Information Server work only with Exchange 2000 Server. Only Outlook Mobile Access works with Exchange Server 5.5.

There's More Than One WAG in Town
In early 2002, Microsoft announced that it would discontinue the Mobile Information Server product line. So what does this mean? If you're using Exchange 2000 and you don't plan to upgrade to Exchange Server 2003 (formerly code-named Titanium) in the near future, Mobile Information Server might still be the product for you. However, if you're planning to upgrade to Exchange 2003, you don't need Mobile Information Server because Microsoft will include most of Mobile Information Server's Exchange-related functionality in Exchange 2003. Microsoft is possibly including Mobile Information Server's Intranet Browse functionality and Web security—related features in the next version of Microsoft Internet Security and Acceleration (ISA) Server 2000.

Many other WAGs are also available for you to consider. Most of these WAGs have features similar to those in Mobile Information Server. Four popular WAGs are XcelleNet's Afaria, JP Mobile's SureWave Enterprise Server, the Synchrologic Mobile Suite, and Extended Systems' XTNDConnect Server. Table 1 compares these four WAGs' features with those in Mobile Information Server.

When you're comparing the various WAGs, keep in mind that many of the current WAG vendors will likely go out of business or be acquired in the near future because of the volatile market. So when you're selecting a WAG, consider the vendor's financial stability and strength.

Weighing the WAGs
WAGs can provide significant benefits to enterprises that must support mobile and wireless solutions. If you're in the market for a WAG, your best bet is to look for a WAG that supports multiple devices, data sources, and connectivity options. The WAG should also support industry standards so that you can easily integrate it into your enterprise. Mobile Information Server is a solid WAG. However, it doesn't support many devices and lacks some administration capabilities. In the short term, often the best solution is to implement several WAGs. That way, you can take advantage of the best that each product has to offer.



Contact the Vendors
EXTENDED SYSTEMS
XTNDConnect Server
http://www.extendedsystems.com

JP MOBILE
SureWave Enterprise Server
http://www.jpmobile.com

SYNCHROLOGIC
Synchrologic Mobile Suite
http://www.synchrologic.com

XCELLENET
Afaria * http://www.xcellenet.com