def mk_uni_port_num(intf_id, onu_id):
    """
    Create a unique virtual UNI port number based up on PON and ONU ID
    :param intf_id:
    :param onu_id: (int) ONU ID (0..max)
    :return: (int) UNI Port number
    """
    return intf_id << 11 | onu_id << 4