code: def str_max_bit_rate(self):
          
          upstream, downstream = self.max_bit_rate
          return (
              fritztools.format_rate(upstream, unit='bits'),
              fritztools.format_rate(downstream, unit ='bits')
          )
docs: Returns a human readable maximun upstream- and downstream-rate
          of the given connection. The rate is given in bits/sec.