code: @Override
      boolean ping_i(final boolean fwd) {
  	if (proxy == null) {
  	    return false;
  	}
  	try {
  	    proxy.ping();
  	} catch (final DevFailed df) {
  	    return false;
  	}
  	return true;
      }
docs: Ping the underlying device, return true if alive, false otherwise