A ring-back tone generator system receives an inbound call connection request forwarded from a phone switch (such as an MSC) that receives the inbound call connection request from a caller phone attempting to connect to a target phone (e.g., a subscriber). The ring-back tone generator system initiates generation of a first call connection on which to provide the customized ring-back tone (and/or custom video image data) to the caller phone. The ring-back tone generator system also transmits, based on receiving the inbound call connection request, an outbound call connection request to the phone switch (such as the MSC) to establish a second call connection through the phone switch to the target phone. Consequently, an MSC that normally handles such call processing now relies on the ring-back tone generator system to handle call processing and provide a custom ring-back tone service.