Hi,
If Asterisk CANCEL a call to OpenSer then Asterisk resends the CANCEL many times because it ignores the 200 OK from OpenSer.
I think this is an OpenSer bug because the 200 OK to the CANCEL contains a To_tag different of the To_tag in the 180 (RFC 3261 in 9.2 says they SHOULD be the same To tag).
I've reported the bug but sincerely I'd like you to read it since I'm sure many people work with Asterisk and OpenSer and could know something about this CANCEL issue:
http://sourceforge.net/tracker/index.php?func=detail&aid=1818469&gro...
Thanks for any comment.