code: protected void doResponse(SipServletResponse response)
  			throws ServletException, IOException {
  		if(logger.isInfoEnabled()) {
  			logger.info("SimpleProxyServlet: Got response:\n" + response);
  		}
  		if(SipServletResponse.SC_OK == response.getStatus() && "BYE".equalsIgnoreCase(response.getMethod())) {
  			SipApplicationSession sipApplicationSession = response.getApplicationSession(false);
  			if(sipApplicationSession != null && sipApplicationSession.isValid()) {
  				sipApplicationSession.invalidate();
  			}			
  		}
  	}
docs: {@inheritDoc}