With the long-awaited Windows 2000 making its appearance earlier this year, it wasn't too long before its sister, Microsoft Exchange, made a debut. In many ways this is the very first product to showcase the benefits of the new operating system - in particular Active Directory (AD).
Microsoft Exchange 2000 pushes scalability, manageability and performance beyond the capabilities of its predecessor, Exchange 5.5, but the implementation of this messaging platform requires a full commitment to AD to squeeze out all of the benefits.
The reason is that Microsoft has replaced the Jet database that formed the storage structure of Exchange 5.5 with AD. In addition to giving network managers a single directory infrastructure for Windows 2000 user management and Exchange 2000 messaging services, AD offers a substantial improvement over its predecessor.
Storage
Most important is the storage of information. With Exchange 5.5 each server had to have an entire copy of the Jet database to work properly. This introduced a massive overhead in replication and was difficult to manage effectively. With AD, information is stored inside the Global Catalogue. This cuts down on this problem dramatically.
The only downside with the way that the product works is for companies that haven't completely made the transition to Windows 2000 and AD, Exchange 2000 is not going to be a 'must buy'. The implementation considerations will mean that many customers will have to stick with Exchange 5.5 for the mean time.
Many companies already in the middle of a complicated and sometimes painful Windows 2000/AD implementation will be able to use Exchange 2000 to centralise email and user administration on ADs.
The unification of management capabilities will also make the security of AD more important than ever because an intruder gaining AD privileges could devastate messaging. The uptime of AD and Global Catalogue servers also becomes more important because authentication cannot occur without ADs.
Network managers will also need to take a step back and decide just how much of Exchange 2000 they should implement and when they should roll out each feature. In addition to new core email capabilities, Exchange 2000 introduces instant messaging, chat and multicast videoconferencing. As the majority of users mostly use email it would be wise to consider additional options only when the need arises.
Where videoconferencing is concerned Microsoft stacks the deck, as it requires the purchase of Exchange Conferencing Server. Installing on to a dual processor Dell PowerEdge 2450, we found that these new capabilities were relatively easy to set up and manage in our test Lan. However, we recommend that companies perform network and message traffic modelling and testing before implementing these solutions in a corporate Wan or between business partners.
Message store
Firing up the management console, which is based on the Microsoft Management Console (MMC), we took a look at the features that lie under the bonnet of the new release. The first major difference we noticed came from the way that messages are stored.
In Exchange 2000, the message store is more modular and manageable than in Exchange 5.5, which should make Exchange 2000 more useful for vendors that outsource email services. The message store can be partitioned into storage groups, which allows multiple user groups to share a single email server.
The important benefit of this architecture is that storage groups can function as independent units - a structure that will allow administrators to do repair or file-restoration jobs on a data store without affecting the other stores in the storage group.
When using previous versions of Exchange, it has been known for network managers to take an entire server offline if a database became corrupted or an in-box required restoration.
Exchange 2000 is significantly faster than Exchange 5.5 in handling the core internet mail protocols SMTP and POP3. Network managers who are already planning a large-scale Exchange 5.5 deployment in an ASP environment or a site with heavy traffic should strongly consider it over its predecessor.
However, they must think about upgrading their servers to squeeze optimal performance from an Exchange 2000 box. Microsoft does recommend that users run the AD server on a separate machine. (In tests, we ran both AD and Exchange 2000 on the same box.)
On running, the AD server, which stores user information and handles authentication chores, was not really taxed, which leads us to believe that the server could cope with supporting the load of additional Exchange 2000 servers. However, it would be crucial to provide redundancy for this server so that a crash wouldn't bring email services to a grinding halt.
Improvements in performance and manageability, and the inclusion of new features such as videoconferencing and instant messaging greatly expand the versatility of Microsoft's flagship messaging platform.
The improved performance and manageability should allow network managers to develop scalable messaging services requiring less network and IT management. They will realise the full gains only if they use AD as the primary user management directory.
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