OpenSER 1.2.0 released on March 12, 2007. See details here.
Trace: » flags » index-examples » t_check_trans_comments
t_check_trans() with ACK (a bug?)
In a simple call setup scenario INVITE / 100 (Trying) / 180 (Ringing) / 200 (OK) / ACK, t_check_trans() returns false when processing INVITE, and it returns true when processing ACK (it must return false since ACK does not belong to INVITE transaction). Moreover, when t_check_trans() is called second time, it always returns false when processing INVITE, but it now returns false also in case of ACK [E.Gabrielyan 2007-04-13].
