The relationships among the CTI server, the various desktop phones, and the different desktop computers are important factors when implementing a CTI solution. In most cases, the server will be on a network (e.g., a LAN) accessible by the desktop computers. This gives the desktop systems access to a variety of telephony information and services, such as sending and receiving faxes, retrieving voice mail, or receiving information about a call being routed to the desktop phone.

Two different strategies can be deployed between the desktop phones and the CTI server. All the desktop phones can be connected to a PBX and the PBX connected to the CTI server; or the phones can be directly connected to the CTI server through one or more specialized telephony adapters.

The relationship between the desktop phone and computer can take several forms: They can be unconnected from one another, interconnected, or totally integrated (as in the case of a home telephony solution). The CTI server can coordinate the activities of the desktop phone and computer regardless of their level of integration. In other words, the decision on how to integrate the desktop can be driven by business requirements instead of technology requirements.

One common element across all the various server-phone-computer relationships is the wiring. Specifically, the physical wiring for the desktop phones (or the phone function) is separate from the wiring for the computer network. The main reason for this separation is that most LANs are not designed to carry real-time voice conversations. In this environment, you can dial your call over the LAN (i.e., your desktop computer tells the CTI server what number to dial), but the actual call occurs over the telephone network. The deployment of high-speed networks that support simultaneous data and voice/video transmission (e.g., Asynchronous Transfer Mode, or ATM, and isochronous Ethernet) will, over time, eliminate the dual-cabling requirement.

Figures A1, A2, and A3 show three examples of desktop configurations that illustrate these CTI concepts.