Just to be clear ports 80 and 8887 are the internal ports.
On my Tablo it looks like this:
Private IP address is 192.168.1.221
Public Port → Private Port
21041 → 8887
21040 → 80
On my router the port forwarding looks like this:
Service Name External Port Internal Port Internal IP address
Tablo1 21041 8887 192.168.1.221
Tablo2 21040 80 192.168.1.221