Background:
I've been tasked with my company's migration from Exchange 2010 to 2013. In coming up with viable scenarios, I've pulled our license data to see what we're licensed for. We appear to have one Exchange 2013 Standard license, one Exchange 2013 Enterprise license, and 250 CALs of both Standard and Enterprise types.
In our current 2010 deployment, we have a dedicated CAS server and two DAG servers. We're broadly trying to simplify our server landscape, and in reading recommendations for deployment, I see that mixed-role servers are recommended. My intention is to deploy two mixed-role servers with round-robin DNS allocating connections between them and databases duplicated on both. We have a little less than 250 users, which fits with the CALs (my understanding is that those aren't a total of 500 CALs, but rather that the 250 enterprise CALs "upgrade" the 250 standard CALs).
My questions:
- Can I deploy two mixed-role servers using the two Exchange Server licenses (one Standard and one Enterprise) that I have?
- Should I, for simplicity, install them both as Standard, and is that covered by the licensing (i.e. can an Enterprise license "fall back" to cover a Standard installation)? I realize that this will limit me to five databases, and I'd also lose any benefit of the Enterprise CALs.
- If I have to install them as their specific editions (one enterprise and one standard), will they coexist fine, and will round-robin-ing between them cause inconsistent user experiencing depending on which a user connects to?
- If the answer to #2 is "no that's not covered" and the answer to #3 is "no, it would be bad", Would an old-style deployment scenario where we use the Standard license to cover a CAS-only server and the Enterprise license to cover a mailbox server enable us to have >5 mailbox databases (even if we still lose the functionality of the enterprise CALs)?
- Is there something else about this that I'm missing?
Many thanks in advance for your help!