private ArrayList getLocalViaHeaders() throws IOException {
    /*
     * We can't keep a cached copy because the callers
     * of this method change the viaHeaders.  In particular
     * a branch may be added which causes INVITES to fail.
     */
    if (viaHeaders != null) {
      return viaHeaders;
    }

    ListeningPoint lp = sipProvider.getListeningPoint();
    viaHeaders = new ArrayList();

    try {
      String addr = lp.getIPAddress();

      ViaHeader viaHeader =
          headerFactory.createViaHeader(addr, lp.getPort(), lp.getTransport(), null);

      viaHeader.setRPort();

      viaHeaders.add(viaHeader);
      return viaHeaders;
    } catch (ParseException e) {
      throw new IOException(
          "A ParseException occurred while creating Via Headers! " + e.getMessage());
    } catch (InvalidArgumentException e) {
      throw new IOException(
          "Unable to create a via header for port " + lp.getPort() + " " + e.getMessage());
    }
  }