No text cut and paste.
The baud rate actually has to be set correctly in the firmware before the connection works.
The command line to invoke for the IP address 1.2.3.4 port 23 is:
mame -rp . vt240 -window -nothrottle -host null_modem -bitb socket.1.2.3.4:23
These are some useful articles that I read in getting it working.http://www.bitsavers.org/pdf/dec/terminal/
https://github.com/larsbrinkhoff/terminal-simulator/issues/1
https://www.mail-archive.com/simh@trailing-edge.com/msg09086...
https://forums.bannister.org/ubbthreads.php?ubb=showflat&Num...
https://simh.trailing-edge.narkive.com/qgzCvrl8/dec-vt-emula...