That’s right.
I have seen a number of mentions on Ser2net in this forum and the website itself is sadly not the most explanatory I've seen. It sounds like it provides you with the ability to hold (host) all your phsyical serial devices USB, RS232 and then allow them to be reference-able via an IP and Port combo.
Indeed, that’s what ser2net does (and it’s the only thing ser2net does).
Also there are dedicated pieces of hardware that do the same TCP/Serial bridging. Here are a couple: WIZnet Official - Leading Internet Connectivity Solutions 404 Error
Do you use the plugin created by Guessed ?(http://forum.micasaverde.com/index.php/topic,2989.msg12655.html#msg12655)
I used to, but then MCV added the ability to connect to a host+port directly into the Luup extensions (luup.io.open()) so I use that instead now in all my plugins.