realport not displaying any output

I am new to realport.

I’ve been trying to get realport working on our Redhat machines (RHEL 7 and RHEL 8). Using minicom to troubleshoot, I do not get any outputs or echos from the port server.

I have had a loopback plug put on the port server, and can confirm that it does echo back what is typed when connected locally (telnetting to the port server and connect 1).

Also, with a modem connected, I can call my cell phone.

When I connect from the Redhat machine with minicom, I can call my cell phone there as well, but no output.

Interestingly enough, if I connect locally on the port server, I do see what is typed from minicom and the modem responses (OK, ERROR, etc).

I have tried 1.9-29, 1.9-38, and 1.9-40. Note on RHEL 8.6, I get a compilation error, due to the kernel header sched.h change, as documented in

I made his suggested change, and it compiles and seems to work. Ie, I was able to call out, but no echoes, no responses.

Others have reported a working connection a few months ago with this portserver, probably on RHEL8.5. We no longer have the RHEL8.5 machine.

I did install all the same versions on a RHEL 7.9, that does not have the kernel header issue. But have the same exact symptoms.


We did a reset on the port server and reconfigured it to factory, and it is now functioning correctly on both RHEL 7.9 and RHEL 8.6