I have written a couple of systems that dealt with this. The first system we purchased a 3rd party predictive dialer that would fire a DDE message to specific DDE Server before transfering a call to a specific extension. It was our responsibility to ensure that the phone and DDE server were sync (no biggie). In this situation the Predictive dialer handled the interface between the phone system (TAPI/TSAPI complient) and the network. A predictive dialer is an extremely expensive system that takes a list of phone numbers and depending on system paramters call phone numbers until it gets a connect and then transfers a call to a phone extension. The predictive dialer is used to maximize user (Telemarkters) time. In theory, as soon as the user completes a call, another call would be transfered to them. Wait times for users are measureed in seconds and the profession hates to wait more than a few. The predictive dialer monitors the number of users, the average call time, the desired wait time, average number of numbers before getting a connect (Live Person) and desired hold time to decide when to start calling the next number. In a busy shop, the predictive dialer is multithreading. More than you wanted to know. The other application I worked on was for a four port modem system. It was a cheap dialer that monitored the two of the ports. When one came free, it placed the next call and when it got a connect, the system seek the number in a table and populated a form based on the table entries. The common piece here is that we had what ever system that dialed the number either fire a DDE message to a DDE server or seek the data itself. Phone systems like ATT and Siemans (TAPI/TSAPI complient) have the ability to communicate to the network.

Hope this helps.

Fred