code: static CRBase create(final boolean request, final int type, final byte[] data)
  	{
  		final byte[] opt = data != null ? data : new byte[0];
  		if (type == KNXnetIPTunnel.TUNNEL_CONNECTION)
  			return request ? (CRBase) new TunnelCRI(opt) : new TunnelCRD(opt);
  		if (type != KNXnetIPDevMgmt.DEVICE_MGMT_CONNECTION)
  			logger.warn("unknown connection type 0x" + Integer.toHexString(type)
  					+ ", create default CRI/CRD");
  		return request ? (CRBase) new CRI(type, opt.clone()) : new CRD(type,
  				opt.clone());
  	}
docs: returns a CRI or CRD depending on request