In a blog wayyy back, i complained about how using the Ignis would cause me to experience extreme lag from the host (0 lag, shoot cluster of enemies, enemies start moving in place, keep using it and i get disconnected) and it happened regardless of how good the connection was to the host. No one else but me ever felt the lag, and often while the "host migration" screen showed up, i could see my team still chatting to each other. This would also happen with Vortex or while using the Embolist. Oddly, other players could do as much cpu or gpu intensive actions as they wanted, but i wouldn't get any lag. Only when i did the actions.
I also noted that i did not have a good internet connection. Decent, at best, and poor at the lowest points. Most people then assumed that must be the problem and even on the forums, i got no solution.
Recently however, i noticed that i could use my ignis on as many enemies as i wanted, and i would not experience lag from the host or any sort of issues like that, other then standard fps drops from using the ignis on groups of enemies. I also noticed that i could actually host matches without too much lag (most players say on a scale of 1 to 10 my connection was a 7-9, basically no lag at all or very little lag) but there is a catch. I can only have 1 other player with me.
Any other players who connect all do the exact same thing: They stand there for 1-2 minutes (literally) without moving, then disconnect. I am not entirely sure why they disconnect, as if it was lag they would surely move around a little before disconnecting. Rarely, more then 1 person will join and move around, but then the second person who joined will experience lag that is "unplayable".
I have come to the conclusion that the way Warframe handles connections have improved, perhaps to the point where less data needs to be sent/received, and at the same time it limits how many people can connect based on my connection. My internet has not changed in the past couple years, and still has a decent to poor connection quality, with just a very minor improvement to download speed.
Lately, i have been playing Cassini on Saturn quite a lot, using that level as my primary means of leveling up equipment. In the past few days however, i have noticed that no matter what time i play (evening, midnight, morning, etc) i usually either can't find a game, or the players are lagging too much (over 125 ping) so i have to host. im glad that i am able to host games now, but i have hosted 90% of the past games i have played in the past few days, and since i can only host 1 person, you can guess how slowly leveling my stuff is getting, not to mention when high mastery players join and just sprint around the map not letting me get shared xp. (it just seems those are the players who do that)
I would try to play on harder planets, but no one ever seems to play any other grineer survival missions consistently as cassini.
My current connection speed on a random server in a state across from mine: