Currently I am looking into the Call Progress Anaylsis possibilities on Cisco Callmanager 7.X in combination with an 2921 H323 voice gateway. We are investigating Call Progress Analysis for outbound calls (busy/answering machine/number unobtainable detection). All this information is send inband and is only available if provider gives the correct ISDN message for instance user-busy of SIP message 486 user busy for busy on PSTN side.
No let's presume that this is the case. ICM outbound dialer uses DSP on voice gateway to detect call progress tones in-band. I am wondering if CTI manager of Callmanager also passes on this information using Jtapi or TSP. If you read the Jtapi and TSP documentation there is room for these kind of messages.
When using old pots phone in the past we have seen TSP and Jtapi messages containing the busy information for the line, but we now face the translation from ISDN to VoiP.
Because ICM outbound dialer is using inband call progress analysis (using DSP resources on the voice gateway) my guess is that this isn't possible. Can someone confirm this?
provider network (IP) -> IP data connection to Cisco Metrolan swith 3400 -> IP Mux which converts IP to 2x ISDN 2mbit line -> 2x 2921 with latest IOS version and each voice gateway having one E1 controller on euro ISDN without CRC4. Each gateway has PVDM-3-64 modules for enabling voice channels.