[Serusers] session duration accounting

[Andreas Granig]

Olivier Taylor wrote:
> I think the query u gave is not really correct, the INVITES are the
> beginning of the sessions, I think we must use the ACKs for a real
> accounting of the call.
> Just think, if it takes 30 seconds to the callee to hang on, u will
> overcharge him.
> I just suggest to replace the INVITES by ACKs.

The timestamp of the INVITE in the acc-table reflects the time the 
200-OK is received, so accounting from INVITE to BYE is absolutely correct.

Just my 2 cents,
Andy