code: public void processRequest(RequestEvent req) {
  		
  		if (tracer.isInfoEnabled()) {
  			tracer.info("Received Request:\n"+req.getRequest());
  		}
  
  		// Restcomm Statistics
  		final String method = req.getRequest().getMethod();
  		if (Request.INVITE.equalsIgnoreCase(method)) {
  			this.defaultUsageParameters.incrementCalls(1);
  		}
  		if (Request.MESSAGE.equalsIgnoreCase(method)) {
  			this.defaultUsageParameters.incrementMessages(1);
  		}
  
  		// get dialog wrapper
  		final Dialog d = req.getDialog();
  		final DialogWrapper dw = getDialogWrapper(d);
  		if (dw != null && req.getServerTransaction() == null) {
  			if (tracer.isInfoEnabled()) {
  				tracer.info("No server tx found, for in dialog request, assuming it as retransmission and dropping...");
  			}
  			return;
  		}
  		
  		if (req.getRequest().getMethod().equals(Request.CANCEL)) {
  			processCancelRequest(req,dw);
  		} else {
  			processNotCancelRequest(req,dw);
  		}
  	}
docs: /*
  (non-Javadoc)
  @see javax.sip.SipListener#processRequest(javax.sip.RequestEvent)