def start(self):
notification_center = NotificationCenter()
self._xmpp_subscription = XMPPIncomingSubscription(local_identity=self.sip_identity, remote_identity=self.xmpp_identity)
notification_center.add_observer(self, sender=self._xmpp_subscription)
self._xmpp_subscription.start()
self._command_proc = proc.spawn(self._run)
self._subscribe_sip()
notification_center.post_notification('X2SPresenceHandlerDidStart', sender=self)
