re: High level Exchange 2010 architecture

markga — Sat, 12 Sep 2009 02:23:42 GMT

Brian,

It depends on where your CAS servers are placed. If you have multiple CAS roles in the same AD site then it would not necessarily use the locally hosted CAS. Your CAS array would be load balanced with NLB or HWLB. One note when combining roles, you cannot have NLB and DAG on the same server so you would have to leverage a 3rd party LB.

ISA 2006 would direct all client traffic via HTTPS to the CAS roles via a NLB or HWLB VIP address.

Thus far the beta recommendations are 8 core for CAS and 8 core for multi role (16 max) - The final HW and proc core recommendations will be coming after RTM of Exchange 2010.

http://blogs.technet.com/blogfiles/ucedsg/WindowsLiveWriter/Exchange2010RCavailablefordownload_DFDE/image_6.png

Combined

re: High level Exchange 2010 architecture

Brian — Sat, 12 Sep 2009 01:42:27 GMT

In Exchange 2007 the HUB roll on a mailbox server would see only that HUB being used by clients on the MB server. With all rolls being supported on a each box (even if it's in a DAG) would the clients of one MB server only use that CAS (ala redirect to your CAS) or would they still all be split. How does this impact ISA publishing OWA if all your CAS are on each MB server. With IO requirements being lower and CAS doing all the client connections a single 16 core server with 32GB of RAM looks more attractive than 1 with 4 cores and 4G (HUB) 2 with 8 cores and 16GB (CAS).