Emlee, Your basic plan is fine. Unfortunately there is no white paper on the topic, as of yet. I have the tasks below, but I caution that you test this out in a test configuration prior to performing the steps below.
Let's outline the tasks a little more detailed so you have a better idea. I'll also include some of the issues you'll encounter or will need to address. In addition, make sure you backup your servers prior to performing these tasks.
You have Unity in an existing domain with Ex55. You want to move to Exchange 2000. You have two options. First, you can join the E2K servers to the Ex55 site (which is mixed-mode messaging). Or second, you can install the E2K servers in their own org and do a full migration from the old Unity installation to a new one using the DiRT tool found on Answermonkey.net.
To migrate the first way, in a mixed-mode messaging environment, do the following:
Upgrade your Windows NT domain to Windows 2000 by promoting your PDC and then BDCs to Windows 2000 domain controllers (You probably already know this). If you're moving to a second domain, it is doable, but you'll have issues with the accounts unless you do certain things (I'm leaving them out assuming this is all the same domain. If your going from one domain to the next, let me know).
Once done, install the ADC and set your connection agreements between the Exchange 5.5 server(s) and AD. I'm assuming this is Unity 3.x since you're mentioning configurationsetup. If it's not, please e-mail me and let me know because there are issues with 2.x Unity running with the ADC.
Once the CA(s) is(are) setup
Move the mailboxes over to E2K. Again, I'm assuming this is the same domain, therefore the accounts don't change, only the mailboxes. This means that if it's the same domain, the accounts will already exist and be enabled. I think they can be disabled and Unity still operate if it's a voice mail only installation.
Run the Unity ADSchema Setup on the Schema master. Use the Unity CD and do it directly on the master.
Once the mailboxes are moved,
run configuration setup and make sure the syncher runs. Check the syncher log found in the commserver\logs directory. You should see it sync up with users, distributions lists and then members of the lists. You might need to run it a second time (or just do it anyway to be safe) by running \commserver\configurationsetup\setup /sync.
As for your other questions, Unity can coexist with E2K servers as you ask.
Unity 3.x isn't affected by the ADC being present. Unity data from the Exchange 5.5 Unity monitor does not replicate anything usable (even though some data WILL replicate over)over to AD for the Exchange 2000 Unity monitor. The Sync process basically takes the account information and rewrites it into the AD after the connector is repointed to AD.
My e-mail is rtstone@cisco.com. You can post to this forum, but also send me an e-mail so I can respond back in the forum. I don't monitor the forum normally.
