Before you tell me to check to see if I've opened the correct ports for my xbox, read this:
About 2-3 months ago, everything was well and good with my internet. I'm running on Telstras ADSL2+ connection, on a Belkin N1 Wireless Router Modem (2in1) through an Ethernet cable. Before I began to get major problems, I could basically pull host on most cod games in a damn ground war, still giving 80% or more full bar connection, while downloading stuff from the internet. I could also upload huge videos to YouTube in minutes.
NOW, everything seems to have changed, and I don't know how or why. My download speeds seem to be the same (fast), and NONE of my settings have changed in the router (Xbox in the DMZ and UPnP off, since the Kinect update), nor have there been any updates to muck things up. Basically, one day, as usual, I ended up pulling host in cod, but people playing from my connection could barely keep a stable yellow bar connection. There seemed to be about 2 seconds of ping, and I could be non-commando knifed from over 9 metres away, along with excessive lag-jumping from every player. Once again, no changes in settings, no downloads/uploads going on, no updates which could've affected anything. This basically happened every game I got host, and worst of all, my connection always pulls it off no matter who's in the lobby, even if they have damn cable internet!
It seems as though the upload speeds are basically f'd. I uploaded a 300MB youtube video in about 4-5 hours 2 days ago, which is insanely long, while I can still manage to download 4GB in under an hour!
Anyway, I have never had the need to foward ports, even though I have tried since, and it doesn't help. I'm not capped (50GB of usage a month, barely touch the 1/2 way mark), and downloads work fine.
TL; DR - Upload speeds and hosting on CoD/player host games used to be amazing, now myself and other players can barely get under 1s of ping, along with crap upload speeds since a few months ago.
So, can anyone tell me what the hell is happening? Is it telstra? My mate got Telstra ADSL2 recently as well, and noticed it's really stuffy at times.