code: protected void doBye(SipServletRequest request) throws ServletException,
  			IOException {
  		if(logger.isInfoEnabled()) {
  			logger.info("SimpleProxyServlet: Got BYE request:\n" + request);
  		}
  		SipServletResponse sipServletResponse = request.createResponse(200);
  		sipServletResponse.send();
  		SipApplicationSession sipApplicationSession = sipServletResponse.getApplicationSession(false);
  		if(sipApplicationSession != null && sipApplicationSession.isValid()) {
  			sipApplicationSession.invalidate();
  		}		
  	}
docs: {@inheritDoc}