code: public void timeout(ServletTimer servletTimer) {
  		if(logger.isInfoEnabled()) {
  			logger.info("Distributable Simple Servlet: timer expired\n");
  		}
  		SipSession sipSession = servletTimer.getApplicationSession().getSipSession(((SessionIdPlaceHolder)servletTimer.getInfo()).getId());
  		if(sipSession != null && !State.TERMINATED.equals(sipSession.getState())) {
  			try {
  				sipSession.createRequest("BYE").send();
  			} catch (IOException e) {
  				logger.error("An unexpected exception occured while sending the BYE", e);
  			}				
  		}
  	}
docs: /*
  (non-Javadoc)
  @see javax.servlet.sip.TimerListener#timeout(javax.servlet.sip.ServletTimer)