This article explains the server roles in the exchange server 2007. The exchange server 2007 is bit different when compared to the previous version in terms of the architecture. Instead of just having a Mailbox server and a front-end server to host data and provide a connecting point for client systems (in exchange 2003), these server roles provide improvements in security with servers dedicated to antivirus and antispam functions, message routing and policy compliance functions, and voice mail communications. The below are the server role. This five server roles cannot be installed in the same server, since each server plays different role in terms of the functional play. Except Edge Transport role, all other roles can be installed in the same system. The reason for the above is security, the edge transport role must be installed in the separate machine which should be independent of all the exchange stuff, so that it just act like a gateway server.
1. Edge Transport server role :
• Performs spam and virus filtering at the first point for the entry of the message.
• Stores a copy of certain active directory objects such as valid recipient email address. All incoming messages are matched with the ADAM – Active Directory Application Mode.
• Mainly for security protection.
2. Hub Transport role :
• Replaces the former bridgehead server.
• Used for effective and efficient message routing of multiple messages.
• Also acts as policy compliance management server for both incoming and outgoing message.
• Can also act as an Edge Transport role. (Without having the edge transport role also we can have the email system working by having hub transport role)
3. Client access server role :
• Connective point for the client systems like office outlook client, a Windows Mobile handheld device, OWA and Outlook anywhere.
• Just acts like a front end server.
• Provide more flexibility in providing redundancy and recoverability of mailbox access in the event of the single point of the system failure.
4. Mailbox server role :
• Holds the mailbox information i.e. the Exchange database EDB.
• New CCR – cluster continuous replication technology(which replicate the data transaction b/w mailbox server across WAN).
5. Unified Messaging server role :
• Completely new feature in the exchange server 2007 used for voice mail server of the organization.
• Phone system takes the incoming message , stores in the mailbox server and playback from the phone or by accessing the message from the outlook, OWA or Windows Mobile.
Hope the above would clarify the new server role topology in the exchange server 2007.
Please shoot if you have any queastions.