PortServerII 16 will not transmit serial on all 16 ports. It will receive serial. This unit has been in operation for several years. I can ping it and telnet to it. All port settings appear correct and do not have any stuck processes? I do not have much experience with these but we have two on the same network and the other is working correctly.
Have you had any power fluctuations or storms. I’ve had many systems see partial failure during an electrical surge. I suggest connecting a loop back connector and testing each port.