It appears that this is a recurring problem on the forums, so I'll try to put as much relevant information so I'm not completely redundant (AND maybe, someone here might come up with something that I haven't already tried).
Problem: I can go 30, maybe an entire hour of multiplayer online gameplay (MW3, BF3, etc.) before I get kicked out of my xbox live party and the game session (if MW3) or game server (if BF3). I'm probably the only person in my group of friends that have this problem when we're in an xbox live party and playing (of varying numbers, sometimes 2, 3, 6, size of party doesn't seem to matter here). This seems to happen frequently and consistently, but there's nothing I do out of the ordinary that would warrant frequent disconnects (just happens within regular online gameplay). Typically the I can rejoin the party easily, and go through the frustration of having to rejoin the game session/server/whatever.
This problem started up early last month. I had previously thought it to be a wireless issue - until I got an ethernet cable and the problems persisted. Suggestions? Relevant information below.
What Country/State/Province do you live in? Indiana
Modem brand & model number: Don't know yet, will check, give me another suggestion in the meantime.
Router brand & model number: Rosewill RNX-EasyN4
If Wireless, are you using a white or black external adapter, or an internal (Xbox 360S) adapter? Not Wireless
Things you have tried:
1) Restart XBox 2) Restart Router 3) Restart Modem AND Router 4) Unplug everything from Router except XBox 5) Set XBox IP to DMZ on router 6) Forwarded Ports 7) Clear System Cache
In short, aside from replacing the Xbox, the Router and the Modem - I've probably done it.
Is UPnP Enabled? Yes
Do you have a NAT error? If so, what is your NAT? Nope.
Any Error Codes you encounter: None
Who is your ISP(Internet Service Provider)? Comcast
After you run "Test Xbox LIVE connection" press “Y” for "More Info”. In the pop-up that appears, what are the following values, if shown? (If a value below does not appear for you, just leave it blank.)
W: 0000 - 000B
X: 0001 - 8005
Y: 20A8 - 4800
Z: 0000 - 0000
ID: FFFF - FFFF
L: 0015 - 10F0
Q: 8015 - 100D