Hi All, Currently we are running Exchange 2003 on a single server. We've got hardware on which to deploy Exchange 2007. Here is the topology I'm proposing: - clustered mailbox server environment containing 2 Exchange serversconfigured withCCR - 2 other servers, each running the Hub Transport role Questions: 1. Can the servers running the Hub Transport role also run the Client Acces server role? 2. Can the clustered mailbox servers run the Client Access server role? 3. We currently own 2 licenses of Exchange 2007 Enterprise which will be installed on the CCR servers. Do I need to buy 2 more licenses of Exchange Server for use on the Hub Transport servers? If so, can I buy Exchange 2007 Standard instead of Enterprise? 4. On the Hub Transport servers, since I'm going to have 2 of them, do I need to use Windows Server 2008 Enterprise (to take advantage of the failover features included) or is it acceptable to run Server 2008 Standard? Thanks in advance for your input!

You should wait for an expert to answer but....I have some answers 1) Yes 2) No, on a CCR deployment, you can only run the Active/Passive roles 3) You will need a CAL for each, and I believe the Hub Transport can use Standard 4) Not quite sure

It is already partly answered. I will answer anyway. 1. Yes, you can run CAS and HUB roles on same server. 2. Clustered mailbox servers cannot run any other roles. 3. You need Exchange license for each server running Exchange server in your configuration. 4. You do not need Server 2008 Enterprise. You can use NLB for Hub role if you plan to run Exchange 2007 SP1. NLB can be enabled in Server 2008 standard.

Excellent information. Just to make sure, can I use Exchange 2007 Standard on the Hub/CAS servers, or do all need to be ExchangeEnterprise? Does Standard include the load balancing for the HUB and CAS roles? Thanks very much.

Yes you can run Exchange 2007 Standard on HUB and CAS servers with NLB. NLB isOS feature and both editions of Exchange 2007 supports it. You can see the details of what each edition offers here: http://www.microsoft.com/exchange/evaluation/editions.mspx

Very good. Also, I'm assuming I can install more HUB and CAS instances at a later date, correct? I'm planning on starting with 2, but would like to increase to 3 instances next year if possible. Thanks again.

Yes you can always add more servers later.