While every new version of Exchange Server released over the years has retained some of the characteristics of the previous version, some versions are more innovative than others. For example, Exchange 2000 Server was a huge departure from Exchange 5.5 because it was the first version of Exchange to make use of the Active Directory. Exchange Server 2003, on the other hand, was very similar to Exchange 2000; but with a few new features. In this article, I will explain how Exchange Server 2007 differs extremely from Exchange Server 2003.
New management console
One of the first changes to Exchange Server 2007 you'll probably notice is the new management console. The Exchange System Manager -- used in Exchange Server 2003 -- has been replaced by the Exchange Management Console, shown in Figure A.
|The Exchange System Manager has been replaced by the Exchange Management Console.|
As you can see in Figure A, the management console has been completely restructured. The procedure for performing many, if not most, management tasks is very different now from what you may have gotten used to in Exchange Server 2003. I have dedicated an entire article in this series to talking about how to perform common management and configuration tasks in the new interface.
Scriptable command line
The Exchange Management Console is not the only tool for configuring or managing Exchange Server 2007. Exchange Server 2007 has been designed so any task you can perform through the Exchange Management Console can also be performed from a command line or from a script.
The new Exchange Management Shell facilitates the use of manually entered or scripted commands. Given the complexity of Exchange Server, you can imagine how complicated the scripting syntax is. Fortunately, Microsoft does not leave you completely in the dark. The Exchange Management Console is actually built on top of the Exchange Management Shell. When you perform an action through the Exchange Management Console, the console is actually issuing commands to the Exchange Management Shell behind the scenes. In many cases, the actual command that was used is displayed for you when the command completes. This allows you to more easily learn the command syntax.
For example, if you look at Figure B, you can see the results screen that was displayed after I created a new address list called Test. The results screen actually shows you the Exchange Management Shell command that was used. You don't have to do anything with this command because the action is already complete; you can copy and paste it into a script, should you have the need.
|The Exchange Management Console is built on top of the Exchange Management Shell.|
Automatic client connection
A minor new feature, but a handy one nonetheless, is automatic client connection. When you attempt to connect Outlook 2007 to a user's mailbox, Outlook will automatically determine the name of the mailbox and the name of the server that the mailbox is hosted on. In the past, the username had to be manually entered before Outlook could find the matching mailbox. Now, Outlook retrieves this information automatically by looking at the name of the user who is currently logged in and by querying the Active Directory for the name of the Exchange Server that hosts the user's mailbox.
Another new aspect of Exchange Server is that Exchange Server is now role based. What this means is Exchange Server 2007 is designed to be modular. You can assign one or more roles to each server in your Exchange organization based on the tasks you want each server to perform. Using a role-based approach to Exchange Server deployment allows you to distribute the total workload across multiple servers so no single server is overburdened.
Role-based deployments are also intended to be more secure than traditional Exchange deployments, since selecting a role during Setup installs only the components that are necessary to facilitate that role and nothing extra. Figure C shows a Setup wizard screen that allows you to select the roles you want to install.
|Exchange Server 2007 takes a role based approach to deployment.|
I will discuss roles in greater detail in my future article on planning an Exchange 2007 deployment. Since most of the roles shown in Figure C might be unfamiliar to you, I'll quickly mention what they are:
- Hub Transport Server Role: Used for message routing. This role is required whether you need to route messages between two mailboxes on the same server, or between the Exchange Server and Internet based recipients.
- Client Access Server Role: Similar to the Exchange Front End Server role found in Exchange Server 2003. It provides the Outlook Web Access Interface through which external users may access the server.
- Mailbox Server Role: Required for any server that will be hosting mailbox stores.
- Unified Messaging Role: Acts as an interface between the Exchange 2007 Server and a compatible PBX phone system. This allows voice and fax messages to be placed into user’s inboxes.
- Edge Transport Role: Cannot be used in conjunction with any other roles. Servers running the edge transport role are typically placed in an organization’s DMZ. These servers work to filter out viruses and spam before messages are allowed to flow into Exchange Servers within the perimeter network.
Probably the most significant change to Exchange Server (at least from a deployment standpoint), is that Exchange Server 2007 is designed to run only on 64-bit Windows Server operating systems. As you probably know, 32-bit operating systems are limited to using a 4-GB address space. Windows Server 2003 divides this 4-GB address space evenly between user mode processes and kernel mode processes. This means that Exchange Server 2003 operated with a mere 2 GB of available memory. It was possible to allocate extra memory to Exchange Server by using the /3GB switch in the Boot.ini file, but doing so sometimes has the tendency to deprive the operating system of available Page Table Entries (PTEs).
A 64-bit operating system provides an address space of up to 16 Exabytes (EB). This allows Exchange and Windows to both be more stable because neither is starved for memory. Requiring a 64-bit operating system also allowed Microsoft to increase the cache size, increasing performance while decreasing the performance impact of larger mailboxes.
Backup and recovery
The way that backups are made has also changed in Exchange Server 2007. Traditionally, organizations running Exchange Server have performed streaming backups of their Exchange Servers on a nightly basis. The information store is locked during these backups. The Exchange Server can continue to run, however, because any new transactions that occur while the backup is running are written to transaction log files rather than directly to the database. (This is how Exchange works whether a backup is running or not.) Once the databases have been backed up, the transaction logs are backed up and committed to the database.
Exchange 2007 does things a little bit differently: It uses local continuous replication or cluster continuous replication to make a copy of the database file. A duplicate copy of a database is stored either locally (for local continuous replication) or on a cluster node (for cluster continuous replication). As transaction log files get filled up, Exchange Server uses a technique called log file shipping to send a copy of the log file to the replica database.
The database and its replica will never be completely synchronized with each other because of the way that log file shipping works. The replica should remain within 1 MB of being current, since 1 MB is the size of a transaction log in Exchange Server 2007.
When tape backups are made, they are made against the replica database, not against the primary database. This helps prevent the backup process from impacting system performance.
Without a doubt, the new feature that has received the most press is unified messaging. In case you have been somehow left out of the loop, unified messaging allows Exchange Server 2007 to support voice mail and fax. The basic idea is that compatible PBX systems can be configured to forward voice mail messages and faxes directly to a user's Exchange Inbox. This means that a user now has one central repository for all voice, fax, and e-mail messages.
Another component to unified messaging is Outlook Voice Access (OVA). OVA is similar to Outlook Web Access (OWA), except that instead of using a Web browser to access their Exchange mailbox, users can use a telephone. Using OVA, users can listen to and verbally respond to e-mail messages while on the go. OVA even allows users to interact with their calendar.
There are a number of security enhancements in Exchange Server 2007. All e-mail messages sent internally (within the Exchange organization) are now encrypted and authenticated by default. This means it is now much more difficult for a user to read someone else's mail or spoof someone else’s identity.
Some of the mail sent across the Internet is now also encrypted by default. If your mail gateway server is running Exchange Server 2007, and the recipient’s mail gateway server is also running Exchange Server 2007, then messages flowing between the two organizations will be automatically encrypted, even though the organizations are completely separate from each other.
Some of the previously existing features found in Exchange Server 2003 have been de-emphasized: These particular features are fully supported within Exchange Server 2007, but in most cases they remain unchanged from the previous version. Furthermore, there are credible rumors that Microsoft is considering removing these features from the next version of Exchange. The de-emphasized features include:
- Public Folders
- Store Events
- Streaming Backup
Although Exchange Server 2007 introduces a wide variety of new features, there are a number of features that were present in Exchange Server 2003 that have been discontinued and are not present in Exchange Server 2007. These features are primarily related to interaction with older versions of Exchange Server or other legacy mail systems. The discontinued features are:
- Access to public folders through IMAP
- Access to public folders through NNTP
- Access to public folders through OWA
- Administrative groups
- CDO 1.2
- CDO for Workflow
- Co-existence with Exchange 5.5
- Event services
- Exchange Web forms
- Exchange WMI classes
- GroupWise connector and migration tools
- Installable File System (IFS) support (M:)
- Outlook Mobile Access (and the Wireless Application Protocol)
- OWA rules creation and editing
- Routing groups
- Transport event sinks
- Workflow designer
- X.400 support
More to come
As you can see, Exchange Server 2007 is very different from Exchange Server 2003; in fact, this article has only scratched the surface. In spite of these differences, I believe that Exchange Server 2007 is worth the upgrade. I will conclude this series with my next article, which will discuss the remaining differences between Exchange Server 2003 and Exchange Server 2007; some of the features that I will research include transport rules and the calendar concierge.