if (!sipStack.isAlive())
throw new TransactionUnavailableException("Stack is stopped");
SIPServerTransaction transaction = null;
SIPRequest sipRequest = (SIPRequest) request;
try {
sipRequest.checkHeaders();
} catch (ParseException ex) {
throw new TransactionUnavailableException(ex.getMessage(), ex);
}
if ( request.getMethod().equals(Request.ACK)) {