Internet is lagging/stuttering all of a sudden

I dont know what it is. I’ve tried everything that I know of. I know a pretty decent amount about networking and computer science but I just dont know whats going on anymore, im starting to think either my xbox is having trouble or perhaps its my isp doing something behind the scenes.

Anyway, heres the deal my internet speed is 30 mbps down and 2 mbps up, so I dont think speed is an issue, as my speed is way above the national average (2.3 mbps last I checked), I tried DMZ hosting and port forwarding as well (I usually have DMZ on, had it for years), and while I did at times have good connections consistently, its no longer the case. I tried switching out an ethernet cable thinking maybe its degraded or something (I dont really know much about hardware and wires etc) and it seemed like it was a little better (emphasis on “little”).

I recently decided to plug my xbox directly to my cable modem to remove all firewall issues, and for like a day it felt like it was good, and now its back to stuttering. So a firewall issue is ruled out

heres the symptoms:

[]Internet stutters
]at times my game (sf4) completely stops either for both players or just one
[]I lose connection to people and I often stay in lobbies
]Green bars are almost always unplayable
[]Ive been having to “test my connection” before being able to connect to xbox live
]I dont know if I was just imagining it, but I felt like I had to “really” push my ethernet cable into my xbox. I dont know if this truly had any effect and I cannot rule out a bad ethernet cable or internet connection
Heres what I think the culprits may be:
[]Bad ethernet cables
]Bad ethernet jack on xbox
[]Possibly my modem is going bad (its separate from my wireless router)
]ISP is being a dick
what do you think it is?

Did you run a ping / line quality test?

Might as well run a speed test too while you’re at it to make sure you’re getting your advertised speeds.

Outside source affecting your connection?
Roommate / someone in the house downloading porn?
Your wireless connection has been taken over and your neighbor is downloading porn?

Did you try playing on your wireless to see if it’s jack / cable going into your xbox?

As Exand said a download on the network can kill the speeds on anyone else.

How are you getting your board band internet?
If it is from the local cable company, that all it takes is being neighbors with someone who downloads/uploads pirated software on torrents all day.
As for cable TV internet, you don’t have your own connection, you share one with your neighborhood, its how the cable line is wired.

One line goes into the neighborhood and its get split up by normal coaxle splitters. The one the Cable company uses in that outdoor unit is more of a hub that a splitter, but it works on the completely same principles, instead of a one line in 2 out splitter, its a 10 way splitter. coaxle cable the cable company uses is meant for TV signals not modern Internet.

So if someone if your neighborhood has a demonoid account your screwed for Xbox live.

Here are my results in Ping test and Speed Test
My Upload supposed to be 15 mbps and 5 mbps on the upload. Note this is over a Wireless N network.

You should be getting the speeds you where promised

If you are using a wired Ethernet connection
Also you might want to check on the quality of your Ethernet cable, The line going from your Xbox 360 to your modem/router should be unbroken, one solid cable going the whole way, no points where a coupler or extender is used. The cable should be at least cat 5, cat 6 would be better.

For wireless/ Wifi connections.
Take in considerations the construction of the building you are in. Some building materials can and will interfere with radio waves (this includes Wifi). Metal paneling, some concrete/cement walls and certain paints will block radio signals. A easy test would be seeing how well you pick up radio waves off the air with a TV set, AM/FM radio or even a cell phone (look at your signal bars). You want to test both the locations on your console and the router as well as any in between points.