/**
   * Put the JAIN-SIP stack in a state where it cannot receive any data and frees the network ports
   * used. That is to say remove JAIN-SIP <tt>ListeningPoint</tt>s and <tt>SipProvider</tt>s.
   */
  @SuppressWarnings("unchecked") // jain-sip legacy code
  private void stopListening() {
    try {
      this.secureJainSipProvider.removeSipListener(this);
      this.stack.deleteSipProvider(this.secureJainSipProvider);
      this.secureJainSipProvider = null;
      this.clearJainSipProvider.removeSipListener(this);
      this.stack.deleteSipProvider(this.clearJainSipProvider);
      this.clearJainSipProvider = null;

      Iterator<ListeningPoint> it = this.stack.getListeningPoints();
      Vector<ListeningPoint> lpointsToRemove = new Vector<ListeningPoint>();
      while (it.hasNext()) {
        lpointsToRemove.add(it.next());
      }

      it = lpointsToRemove.iterator();
      while (it.hasNext()) {
        this.stack.deleteListeningPoint(it.next());
      }

      this.stack.stop();
      if (logger.isTraceEnabled()) logger.trace("stopped listening");
    } catch (ObjectInUseException ex) {
      logger.fatal("Failed to stop listening", ex);
    }
  }
  /**
   * Returns the JAIN-SIP <tt>ListeningPoint</tt> associated to the given transport string.
   *
   * @param transport a string like "UDP", "TCP" or "TLS".
   * @return the LP associated to the given transport.
   */
  @SuppressWarnings("unchecked") // jain-sip legacy code
  public ListeningPoint getLP(String transport) {
    ListeningPoint lp;
    Iterator<ListeningPoint> it = this.stack.getListeningPoints();

    while (it.hasNext()) {
      lp = it.next();
      // FIXME: JAIN-SIP stack is not consistent with case
      // (reported upstream)
      if (lp.getTransport().toLowerCase().equals(transport.toLowerCase())) return lp;
    }

    throw new IllegalArgumentException("Invalid transport: " + transport);
  }
  /**
   * Removes from the specified list of candidates providers connected to a registrar that does not
   * match the IP address that we are receiving a request from.
   *
   * @param candidates the list of providers we've like to filter.
   * @param request the request that we are currently dispatching
   */
  private void filterByAddress(List<ProtocolProviderServiceSipImpl> candidates, Request request) {
    Iterator<ProtocolProviderServiceSipImpl> iterPP = candidates.iterator();
    while (iterPP.hasNext()) {
      ProtocolProviderServiceSipImpl candidate = iterPP.next();

      if (candidate.getRegistrarConnection() == null) {
        // RegistrarLess connections are ok
        continue;
      }

      if (!candidate.getRegistrarConnection().isRegistrarless()
          && !candidate.getRegistrarConnection().isRequestFromSameConnection(request)) {
        iterPP.remove();
      }
    }
  }