Ex 2007 Multi Server Deployment Scenerio ?   

Ours is an organization with around 3000 users
We are considering deploying Ex 2007 in a multi server scenerio & we have 
roughly laid down our plan as stated below, but have few doubts regarding the 
Software version to be used.

Our deployment Plan involves

-2 Ex 2007 Edge transport Servers
-2 ISA Enterprise Servers in Windows NLB
-2 Ex 2007 CAS in Windows NLB
-2 Ex 2007 Hub Transport 
-1 Ex 2007 UM
-2 Ex 2007 CCR Pairs Mailbox roles on Win 2003 Ent Edt with MNS Cluster- [in 
all 2 active & 2 passive nodes]
-2 DC's/DNS/GC 

Our query's are as follows

1] We are aware that the CCR feature is supported by EX 2007 Ent Edt & it 
would also require Windows 2003 64 Ent edt, but can we have our UM, Edge, CAS 
& Hub Transport role use Ex 2007 Std Edt running on win 2003 64 std edt. Is 
this supported?

2] We plan to NLB our ISA 2006 so we know we require ISA 2006 Ent Edt, but 
can we run this on Win2003 std edt as all ver od windows support NLB? Also we 
belive ISA2006 is only available as a 32 bit application, is that true?

3] Can we use our existing 32 bit hardware servers to run our Win 2003 DC's 
& DNS's in the new Ex 2007 multi server deployment that we are planning?

4] or is it that in an Ex 2007 CCR deployment scenerio requires all other Ex 
2007 roles such as CAS, Hub & Edge server to be using Ex 2007 Ent Edt only. 
If yes, then can these CAS, HUB & Edge using Ex 2007 Ent Edt be run on Win 
2003 64 Std edt

date: Sun, 2 Dec 2007 23:17:00 -0800   author:   Vicky