I have a few questions about Cisco Unity before implementing it into the domain or creating it's own.
1- How does the unity software interact with exchange, does it modify objects or add properties (like it does to A.D.) ?
2- Can it be set up for Unified messaging and still have it's own domain (Windows 2003 standard server) and Exchange 2003 separate from the existing servers?
3- If so, does Exchange 2003 have to be installed on a separate machine or can it be installed on the Unity server itself?
Any help would be greatly appreciated.
Unity does update or add atributes to AD to make the object Unity enabled. The attributes are basically hidden. AD and the Unity SQL database are exact copies of the AD directory.
Unity can be in it's own domain for VoiceMail only setup. Unified messaging would not work for this type of setup. The whole defination of Unified is having one mailbox for voicemails, emails, faxes, etc. With an understanding of AD, AD can only have one Exchange Org with multiply servers. No matter any way you slice it, UM/Unity will use this infrastructure and update your schema. If you choose a seperate domain, then it turns Unity into a Voicemail setup.
It is recommended that Unity be installed on a seperate server in the same LAN as the the Exchange is installed on. Unity will then need to be connected to your existing PBX or callmanager. In a voicemail only setup, you can install Unity/SQL and the messaging store all on one server for a smaller rollout.(1-500 subscribers anything more, I would go failover and seperate messaging store)
There are great docs on the Cisco site that go over design scenarios. Also, I highly recommend pickup the holy bible of Unity. "Cisco Unity Deployment and Solutions Guide" It will answer every question you have.
hope this helps.