When multiple applications are running simultaneously, an appropriate one must be found to become the initial owner of each incoming call. In general, incoming calls reach their destination, or target application, in these steps. First, the service provider learns of the new call and passes it to the TAPI dynamic-link library which gives the call to the appropriate application. Finally, applications conduct probing, if necessary, which can cause the call to be handed off between applications one or more times. These steps are described in the following topics. Sometimes applications perform further probing, a case which is also covered in the following topics.