What is the "park-agent" service used for?

By the time you've made this question u probably already know the answer... But here goes the answer: This port is related to uPNP services. I've made a port scanning on my home router and found this "park-agent" port opened in it. After some research on the internet I read some people talking about uPNP. Then I decided to disable the uPNP service on my router and bingo! The port has been closed! I just don't know how exactly uPNP works but i read that it allows devices that "talk" uPNP to search and find each other in your network for communications purposes (i.e. media sharing, and other stuff which idk how it's being shared). So it looks to be insecure if enabled on your gateway or router since you don't want to share through internet your media or anything else you don't know how exactly is being shared to the world. ;)

If its your own system, you could probably run netstat -b (on windows) or netstat -p (on linux) on the system its running on to identify the process- netstat tends to use behaviour to guess what sort of software is running, and what OS, and that description sounds rather generic.

The description "Park Agent" will likely just come from the nmap services file, it doens't necessarily mean that that's what's running on the system.

What sort of host is it that you saw it running on? One suggestion I've seen for that port is UPnP