How to add ping to a ranking box

Hello guys!
I'm having troubles with making a ping column in my ranking that means i don't know how to match player prefab with its NetworkConnection so i can get player's ping. Can you guys give me a hint or maybe even some short code example on how to do it?

 

A ping is the time it takes to contact a server. You can just add a ping function to the server.
Client notes the current time, sends ping. Receives pong asynchronously sometime later, check the time difference, and there is your ping.