As its name suggests, Exchange 2007 is slated for a 2007 release and will bring a slew of new features and a number of changes to the messaging world. Even at this early stage, it's important to know how Exchange 2007 will work so you can make appropriate decisions if you need to make changes to your Exchange organization in the interim. In this issue, I'll go over one of these changes: roles.
The first major change coming to Exchange 2007 is the expansion of roles. Under Exchange 2000 and 2003, you've gotten used to the concept of "front-end," "back-end" and "bridgehead" servers handling your organization's mail. With Exchange 2007, these roles still exist—with different names—and their functionality has been slightly changed. In addition, Microsoft has added some new roles to the mix. I'll explain each role below:
- Client Access: Provides access to mailboxes through Outlook Web Access, POP3, IMAP4, RPC over HTTP (called Outlook Anywhere in Exchange 2007), and Exchange Server ActiveSync.
- Edge Transport: Provides mail security tools, such as antivirus and anti-spam protection, at the network perimeter.
- Hub Transport (formerly bridgehead): Provides internal transport, routing and message compliance policies to the Exchange organization. The Hub Transport is tightly integrated with Active Directory in Exchange 2007. This integration will be explained further in another tip.
- Mailbox: Provides mailbox database hosting services, which contains users' e-mail, calendar, contact, and task information.
- Unified Messaging: Unified Messaging, the ability for users to receive voice mail, e-mail, faxes, and calendar information in a single mailbox, comes to Exchange 2007 and stores all of these items in a user's Exchange inbox. Unified Messaging also provides some advanced features, such as the ability to access an Exchange inbox from a phone, and Automated Attendant functionality.
Two questions that have been asked about this new role system are:
- Can you run multiple roles on a single server? Yes, with the exception of the Edge Transport role, all roles can run on a single server. Exception: Under a clustering scenario, the Mailbox Transport role must be on its own server as well.
- Do you need to use all of the roles? Yes, with the exception of the Edge Transport role, you must have the remaining roles in use somewhere in your Exchange organization.
Windows roles have helped administrators load only the functionality needed to provide a particular service and help to reduce the attack surface. Hopefully, this functionality in Exchange will help to achieve the same goal and also make Exchange more easily scaled.