You are the messaging engineer for your company. You are planning to transition from Microsoft Exchange Server 2003 to Exchange Server 2007. During the transition, both versions of Exchange server will coexist on your network.
You need to design a transition plan that supports the following:
Microsoft Office Outlook 2003 clients that use RPC over HTTP connections
AutoDiscover service for Outlook 2007 clients
Outlook Web Access for mailboxes on Exchange Server 2003 mailbox servers
What should you recommend?
A.
Install an Exchange Server 2003 front-end server and an Exchange Server 2007 Mailbox server. Move all
mailboxes to the Mailbox server.
B.
Install two Exchange Server 2003 front-end servers. Create a Network Load Balancing Cluster between the
two front-end servers.
C.
Install an Exchange Server 2007 Client Access server, a Hub Transport server, and a Mailbox server. Move
mailboxes to the Mailbox server.
D.
Install two Exchange Server 2007 Hub Transport servers. Create a Network Load Balancing Cluster
between the two Hub Transport servers.
Explanation:
Any choice not involving the CAS role wont work.Client Access role is similar to the FE server in 2003. It handles all connections, whether from Outlook 2003 or 2007, Outlook Express, or any other MAPI, POP3 or IMAP4 client; as well as connections from OWA, Outlook Anywhere, or any mobile device using ActiveSync. Outlook Anywhere (RPC over HTTP in 2003) provides Internet access to an Exchange environment, without needing either VPNs or RPC ports open in the firewall.
http://www.msexchange.org/tutorials/Introduction-Exchange-2007-Server-Roles.html
http://technet.microsoft.com/en-us/library/bb123741.aspx