It’s been a while since I last did one, but you need to select port configuration as I recall. Then choose TCP from the drop down list at the top of the screen and enter the parameters below it.
I can fire up my BX982 and have a look if you’re still stuck.
I’m not around the system now, but I think clicking “port configuration” takes you to the top port on the list. From there you can edit the settings.
You can also click the name of a port under the Type column to edit them.
The problem I’m having is that when I change the settings of a port, then click “OK” at the bottom, it takes me back out to the port summary but nothing is changed. I must be missing something.
I wonder if I can or should add a new port. I don’t see an add button anywhere though.