My Nat is open and my packet loss rate is low/excellent, yet my upstream bandwidth is in the warning zone, my internet its how its been for a few months now, yet for the past week ive been dropped from moderate to warning, does anyone know how to fix this?
Apart from seeing if your ISP has a level of service with faster upload, you could try a new router. That was the problem with mine, apparently. Needless to say, this may or may not be your problem, so if you’ve got a different router you can use for a while to check or can connect your Xbox directly into your modem for a while I’d give that a try before running out to buy a new router.
My game-play quality has gone to crap lately. It is right now the worst it has ever been!
I have always had a closed NAT. Packet loss rate is low/excellent, but my upstream bandwidth is “undetected”. My guess would be that’s bad. I have some videos in my file share to demonstrate just how bad my internet is, but the weird thing is that when I first started playing Halo: Reach on September 14th 2010 I hardly ever encountered lag such as I am experiencing now, but I have run an internet speed test and I am still getting the same amount of megabits that I have always been getting!
So, could it be my router? No, I got a new router… I don’t know >_< !!!
It is so frustrating to loose not because I am lacking skill, but because my internet is so slow. 
Mines always been “Undetected.”
I always get good or warning (the latter most of the time). It’s not your connection as a whole but rather how well it will do if you pull host. Luckily i don’t but my games are pretty smooth unless it’s against a foreign host or egotistical players from Mexico (note that i am Mexican myself and not being racist in the slightest.)
Upstream doesn’t matter in Reach (unless your is something really appalling like 0.01).
But if you pull host i doubt everyone else will be enjoying it.