Sample Flow 5 Out-of-band Ringback with Progress Message

When there is no progress indicator included in either the Alerting or Progress messages, then there is out-of-band ringback. The system maps the Alerting message to a SIP 180, but it does not include SDP in the SIP 180. This call flow shows includes the Progress message; still, media cannot be set up until after H.323 Connect and SIP messages are sent.