6.3  

Conditions for Domain Controller and Terminal Server 
 
The operation of a telephony server requires a Windows Domain including a Domain Controller due to Microsoft's TAPI architecture. In the easiest case the Domain Controller could be the PC as the telephony server. On the PC with the telephony server however there has to be Terminal Server / Citrix installed too.
But Microsoft advises against the installation of a Terminal Server on a Domain Controller due to performance and security issues. Therefore it is to consider that the Domain Controller is installed on a different PC than the combination of telephony server and Terminal Server / Citrix.
Only for pure test operation - however not in productive environment - the Domain Controller can be installed on the same PC along with telephony server and Terminal Server.