I had a go at getting it to work online with the GOG Edition using YANG - Yet Another Netplay Guider that is a netplay launcher that helps players advertise their game rooms on a server so people can easily join them.
It's important to also know that, making sure that inside the game the "Sky" and "Reflections" are off by pressing the D button to disable them in the menu to prevent a crash that can happen at anytime during your game some of the times.
I think the GOG Edition has them off by default.
The game doesn't seem to ever crash with those options off, so far.
You can also use the R key to go to a better resolution that looks nicer without problems.
And here is a video using the GOG version, setting it up for Multiplayer purposes with YANG -
https://youtu.be/RW4UEOgZkYs.
And you get to see the game actually connect over the internet, with a ping of around 50ms that was quite playable.
Again sadly this game I think wasn't designed to be played over the Internet, but it can be played over the internet, just maybe not with players with a higher ping way over past 50ms, but you can try.
So I recommend playing someone in the same country as you or not to far, with 50ms or lower ping as a guide only.
LAN games will be great no doubt.
The GOG edition has a shortcut "DOSBox Configuration", to alter some settings to improve the performance of your DOSBox. That's one of the things I haven't altered much in the video.
On YANG (Yet Another Netplay Guider) - you can use a DOSBox configuration file as a base.
For those that would like to try YANG the main website is -
http://yang-online.com.
If you are just using the GOG Edition to play online, it comes with a "Launch Multiplayer" shortcut that allows you to enter the IP address manually to play someone over the Internet or just over your LAN.
If using the GOG Edition only without YANG, it will use the default port for the DOSBox HOST port UDP 213 that you can forward if acting as the server the HOST, joiners won't have to forward the port.
YANG by default uses TCP port 8501 for the room hoster, and the UDP port 23513 by default for the DOSBox IPX Server.