super.doStart();
Properties properties = configuration.createInitialProperties();
sipStack = configuration.getSipFactory().createSipStack(properties);
configuration.parseURI();
sipSubscriptionListener = new SipSubscriptionListener(this);
ListeningPoint listeningPoint =
sipStack.createListeningPoint(configuration.getFromHost(), Integer.valueOf(configuration.getFromPort()).intValue(), configuration.getTransport());
configuration.setListeningPoint(listeningPoint);
provider = sipStack.createSipProvider(configuration.getListeningPoint());
provider.addSipListener(sipSubscriptionListener);