@staticmethod
def get_dns_length(bts):
    """
        return -- length of DNS name including terminating 0 (if present)
        """
    off = 0
    while off < len(bts):
        if bts[off] == 192:
            return off + 2
        elif bts[off] == 0:
            return off + 1
        off += bts[off] + 1
    return 0
