The 25 pin D-Sub connector fits on the back of the IF-AN 24, sending out 8 channels to or from your patch bay / mixer, either balanced jacks or XLR female or / male.
3 x 25 pin D-Sub to 8 channels inputs & outputs so 6 multicore looms in total. You probably only need one 25 pin D-Sub 8 way multicore loom for the recording inputs if you are recording 8 channels or less at one time, as you can actually assign the inputs to record on any channel.