I'm 100% agree that players can play on the server who have got 250 ping because they are far from the server. I totally accept it. No problem.
But if someone play with unstable network and he's got 'jumping' ping that's totally unacceptable for me.
Let's imagine a situation. You and your brother have the same network and he start to watch HD videos on youtube, or start to download on torrent, your ping can be very high, and it can be jump up and down. This can be really annoying for others, because u can teleport, or act like a tank on DD mode. Furthermore, it's annoying for you too because you can't play with that accuracy as you play with normal ping. This situation is happening with me frequently. In this case the best solution is to quit the game and wait while the lag (or your brother) goes away and you can play more in peace.
So, I'd like to ask every player if they have this "jumping" ping, please leave the server and come back when lag gone.
Thank you.