I've deployed this recently and had to add these registry keys to manually set the servers. (.1 as primary server keys and .2 as secondary server keys). I know that this worked to automate the servers in the deployment.
Also, we upgraded our call manager to authenticate to Active Directory instead of with the Computers Mac Address, and these are the registry changes that I made to put the description in as well as change it to authenticate off of description.
The actual servers are stored in DWORD Decimal format and need to be passed in that way. Here is how to turn a IP into Decimal format using 10.160.0.1 as a test case. Use this formula: (((((((A*256)+B)*256)+C)*256)+D)) where A=10, B=160, C=0, and D=1. So the decimal for ip 10.160.0.1 is 178257921. You can ping that number just like an ip and the numbers are interchangable. For some reason, when IP Communicator calls the decimal from the registry, it formats it backwards, so you need to use (((((((D*256)+C)*256)+B)*256)+A)) for this install only. I hope this helps. I wrote a script to autofill the username (formatted however you need for callmanager) and to populate the correct fields, let me know if you need this. Thanks!