Are my CAT5 and router my weak link?

Personnally I believe that you are transmitting data and that the DAC and Router are probably designed to work with mediocre wire. Although I see that some companies such as AudioQuest are offering high-end cabling for ethernet and Cat7. So maybe they have found some performance advantage or just an extension of another profit center. But years ago we thought an interconnect was just an interconnect and the power cord was just a power cord. Someday I wonder if we will see some type of air ionizer that we can filter the air in our listening room to enhance the effortless flow of soundwaves between the driver and the ear. I just hope it is quiet!

Jeffatus, Time jitter is the only thing that affects sound of digital transmission. Wireless or Ethernet data is just that - a data. It means it is being sent in packets without timing. Bad Ethernet cable or wireless router can cause disruption is data delivery resulting in dropouts but cannot change the sound.

Kijanki is correct.