Typically, any computer with enough processing power to run Windows Server can act as a telephony server, linking client computers to hardware, such as a Private Branch Exchange (PBX).
Other services, especially server-side telephony programs, may have different requirements.
Remember that, if the telephony server is the PBX, it may make additional processing demands.
Obtain service provider components required to communicate with a PBX from a PBX vendor or reseller.
The Telephony service does not include the service provider components required to communicate with a PBX.
Like networking software, a telephony program must be secured to protect privacy and data integrity.
The Telephony service must run on a computer that is a member of a Active Directory Domain Services (AD DS) domain, and all telephony client users must have valid domain accounts. The domain administrator defines which users have permission to communicate with the PBX, and the telephony server administrator defines which lines those users can access.
Telephony client and users must be in the same domain as, or in a domain trusted by the telephony server.
Make sure that telephony clients and telephony users are in the same domain as a telephony server or in a domain that has a two-way trust relationship with the domain containing the server.
Specify the telephony server on a telephony client or install the Windows Remote Service Provider to make lines or phones available to the client users.
TAPI is automatically installed on computers running Windows 2000, Windows XP, Windows Server 2003, Windows Vista, and Windows Server 2008. If your clients or your telephony server are running Windows 2000, you must specify a server on the telephony clients before the server's lines are available to the client users. On newer operating systems, you can use the Windows Remote Service Provider on clients so that they can automatically detect the server and configure themselves properly.