Carl Wagner writes:
It looks like the problem is that that "200
Canceling" has a To: tag and
it shouldn't.
where did you learn that?
-- juha
Regardless of the method of the original request, as long as the CANCEL
matched an existing transaction, the UAS answers the CANCEL request
itself with a 200 (OK) response. This response is constructed following
the procedures described in Section 8.2.6 noting that the To tag of the
response to the CANCEL and the To tag in the response to the original
request SHOULD be the same. The response to CANCEL is passed to the
server transaction for transmission.