Decision Support: The pros and cons of an Exchange 2003 migration

Find out what Exchange 2003 has to offer.

It seems like yesterday that e-mail administrators were figuring out how to migrate from Exchange 5.5 to Exchange 2000 and work through the many differences between the two systems. Very soon, administrators will be going through a similar process when they consider a move to Exchange Server 2003, the latest version of Exchange. For those who make the decision to migrate, the orientation and planning process will start all over again. I’m going to help you with the first part of the equation: figuring out what Exchange 2003 has to offer.

Exciting enhancements
Exchange 2003 includes a number of enhancements designed to provide a better experience for both users and administrators. Let's take a closer look at several of these important enhancements.

Security within Exchange and Outlook has been an Achilles heel for Microsoft for quite some. Only time will tell if this trend continues, but Microsoft has made an effort to address some security issues with this release.

One area where security has been taken into consideration is in the use of the full Outlook client from remote locations. In versions of Exchange prior to 2003, a VPN was required in order to provide any semblance of security for Outlook clients outside the firewall. When used in conjunction with the upcoming Outlook 11 (aka Outlook 2003) and Windows Server 2003, a connection to Exchange can be made using RPC calls over HTTPS from Outlook in order to provide a secure communication tunnel between the client and server. This effectively eliminates the need for a VPN connection to the network for simple e-mail access.

Exchange servers can now be secured by using IPSec as the communications protocol. In addition, Outlook Web Access now uses cookie-based authentication and times out connections in order to prevent hijacking of a session just because someone left it open. This is accomplished through the use of S/MIME. As a result of using S/MIME, encryption and signing are also supported in the new OWA.

While not typically considered a true security enhancement, Exchange 2003 does provide one tool that will be of great interest to administrators concerned about being able to easily restore data in the event of a problem: single mailbox recovery.

In addition, Microsoft has updated the VSAPI, the API that handles virus scanning for the Exchange information store. The new VSAPI will allow scanning for viruses on Exchange servers that do not host mailboxes, such as bridgehead servers. This new functionality allows virus scanners to catch viruses before they hit servers with mailboxes.

Performance, scalability, and availability
When used in conjunction with Outlook 11 and Windows Server 2003, Exchange 2003 provides some significant enhancements to the performance of the overall system. First, when used with the new Volume Shadow Copy service, an Exchange server can effectively support more users than prior versions. Using this service, a volume can be immediately backed up to a different location rather than needing to use agents and other slower backup methods. Because of this, more users can be supported without having to worry about the size of the information store.

The new version of Outlook supports a local cache for the user’s mailbox. This feature results in less network traffic, which reduces the load on the server, allows more users to be stored on the server, and increases performance.

Scalability and availability are also enhanced with the use of Exchange 2003 on Windows Server 2003 by the use of up to eight-node clustering.

More connection options
Besides a secure RPC over HTTPS tunnel with Outlook 11 and Windows Server 2003, Exchange 2003 adds support for a wide variety of other types of client devices. Using Outlook Mobile Access (OMA) on the Exchange server, mobile devices such as smart phones, Pocket PCs, and WAP 2.0 devices can remotely access the Exchange information store in real time.

Outlook Web Access (OWA) has also undergone dramatic changes to make it more usable and consistent with the full Outlook 11 client program. To this end, OWA in Exchange Server 2003 uses an interface that very closely mirrors that of Outlook 11.

While Exchange Server 2003 includes a number of improvements and enhancements, not every organization will migrate to it for a variety of technical reasons, not to mention the upgrade costs.

Upgrade requirements
First, Exchange Server 2003 will not run on Windows NT or Windows 2000 SP2 or earlier. Furthermore, any domain controllers or global catalog servers used by Exchange need to be running Windows 2000 SP3 or Windows Server 2003 RC2 or greater. The same requirements hold true for the version of Active Directory Connector provided with Exchange 2003.

In addition, an in-place upgrade from Exchange 2000 running on a Windows 2000 SP3 server requires that Exchange 2000 SP3 be installed. In addition, there is no way to perform an in-place upgrade from Exchange 5.5 to Exchange 2003. The recommended method for an Exchange 5.5 to 2003 upgrade involves buying new hardware for Exchange 2003 and then joining the Exchange 5.5 site and moving the resources to the new server.

Missing components
While adding new features, Microsoft has also removed certain features from Exchange 2003. Included on this list are instant messaging, chat, and key management services. Some of these features will be included in a new product offering from Microsoft that will be separate from Exchange 2003.

It's definitely a package deal
Almost all of the additional features or enhancements to services provided by Exchange 2003 will work only when it is installed on Windows Server 2003 and when the clients are using Outlook 11. As such, this is a package deal.

If you like the fact that Exchange mailbox backups can be done in a fraction of the time now required, you should be prepared to roll out Windows Server 2003 in order to be able to use this feature. Likewise, to use the new caching features or VPN-less remote mailbox access, be prepared to roll out and support Microsoft Office 2003.

New features at a cost
Exchange 2003 should present administrators with the "finished" look that some consider was missing from Exchange 2000. While not a radical overhaul like the migration from Exchange 5.5 to Exchange 2000, significant features have been added, but they come with a cost. In order to make use of them, significant planning and infrastructure work will be required. Also, if you didn’t get software assurance under Exchange 2000, be prepared to pay a hefty fee to upgrade to this newest version.