Database Information

In openUC / sipXecs 4.6 and prior all CDR information is stored in Postgres.

All the information regarding call events is aggregated in the call_state_events table

Additional Information

Configuring Call Detail Records: Configuring Call Detail Recording (CDR)

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Call State Events Table

Column event_type holds the event type sent
R - Call Request
T - Transfer call Event
S - Call Established Event
F - Call failed event
E - Normal End Call event

Below is an example with call_state_events table entries  given from_url and to_url values. These applies when we try to place a call  using a 3PCC

Example: 
when from = user1, to = user1 status=R we know that user1 phone is ringing
when from = user1, to = user1 status=S we know that user1 picked up the phone
when from = user1, to = user2 status=R we know that user2 phone started ringing
when from = user1, to = user2 status=S we know that user2 answered the phone

Failure situations:
when from = user1, to = user1, status=F we know that user1 rejected the call
when from = user1, to = user2, status=E we know that user2 rejected the call (if there is no call established event (S) before, we know that user2 never answered the call and rejected it instead)
(If there is an (S) status event before, then user2 normally ended the call)