The output from jackd on the slave shows that there are only two channels,
and only in one direction:
Send channels (audio - midi) : 0 - 0
Return channels (audio - midi) : 2 - 0
$ jackd -d net --help
...
-C, --input-ports Number of audio input ports. If -1, audio
physical input from the master (default: -1)
-P, --output-ports Number of audio output ports. If -1, audio
physical output from the master (default: -1)
-i, --midi-in-ports Number of MIDI input ports. If -1, MIDI
physical input from the master (default: -1)
-o, --midi-out-ports Number of MIDI output ports. If -1, MIDI
physical output from the master (default: -1)
Try setting the -C and -P values.
--
Chris Caudle