According to the specification (JSR 289, section 188.8.131.52.2) the
SipApplicationSession should be marked as Ready-To-Invalidate upon a CONFIRMED
state of the SipSession. This seems not to be the case.
The behavior can be reproduced by deploying a non-record-routing proxy
application, together with a SipApplicationSessionListener. The method
"sessionReadyToInvalidate()" never gets called. Eventually "sessionExpired()"
will be called, but even then, "isReadyToInvalidate()" on the SAS returns false.