Idea is that when found all ports on pc
Years ago, with a VAX computer at a school, we used multiplexers which were boxes that had 16 RS232 ports to connect to terminals or printers, that would squeeze all those ports over a single long cable (two twisted pairs, I think it was, one pair for each direction) with a matching box at the other end to expand it all back out again into a matching number of serial ports on the computer. I think we had more RS232 ports at that place than existed in the rest of the town put together!
So I'm kinda interested in what you're doing
1/ What are the serial devices that are hooked up to the PC(s)? Like, gas analysers, scales, keypads, GPS, ... ?
1b/ What do the packets look like? Fixed or variable size? ASCII or binary? Delimited? How large on average?
1c/ How many packets per second does an average device typically emit?
1d/ Is the dataflow unidirectional, or is there also data coming back from the computer to the devices?
2/ Are you using an actual multi-port serial card that plugs inside the computer, or a number of USB serial adapters via USB hub(s)?
2b/ If USB... can you stack up the hubs, ie plug hubs into hubs? Have you found that to be reliable?
3/ Are you thinking to put all the serial channels through the one IP network port number, or allocate one port number per serial channel?
4/ How many serial ports/devices are we looking at? Per agglomerator, and in total. Five? Fifty? Five hundred?