I ran an Amiga BBS here in Texas for some time in the early and mid 90s before the Internet boom and used CNET when it was under Perspective Software, with ISDN. For a time during that I had the 486 bridgeboard running Wildcat from Mustang Software with a null-modem hookup to one of the GVP or ADSG serial boards that you could connect to through a mod that could dial out to other BBS' through CNET. (I forget how many phone lines I had, it was more than 3) This was using a A2000 with a GVP Tekmagic 060 w/128 MB, 12 GB of SCSI drives and a cdrom changer ( I forget how many discs it could hold, I think it was 7, it was from Plextor)
The only thing I have left of all that is the A2000 with the accellerator, hard drives and the serial boards and the software.
I never messed with the TCP/IP but really liked CNET.