US Patent 7245707 Data network based telephone messaging system

A sending device exchanges handshake signals with a recording device prior to the delivery of voice messages. The sending and recording device are remotely connected using a data network. In one embodiment of the present invention, the data network provides different levels of quality of services (QOS). The voice message can be sent using a low QOS level that permits long delays between voice-based data packets. On the other hand, the handshaking negotiation (e.g., the status request and acknowledgment packets) is carried out using a higher QOS level that permits shorter delays. By knowing the status of the recording device before recording, a user will not waste time to record the voice message.