In anticipation of the MCC, I decided to load up Halo 4 last week on my 360.
I have to admit, this has been the most painful Halo experience to date.
Lizard Squad antics aside, in the last week of playing I have been dropped from XBox Live when playing Halo 4 Multi-player every 1-2 games.
If I am not dropped from XBL, when a game is complete the connection to the Halo Servers is dropped and all the playlists appear to be offline.
I relaunch the game and this usually corrects the Halo Server issue, but the XBL disconnects are forcing me to reboot my router and 360 in most instances.
The XBL error that is being generated is 80151909. http://support.xbox.com/en-CA/xbox-360/xbox-live/error-code-80151909
This is not a question of my NAT, ports, internet connection or install. All my other games and apps run fine.
What is the problem here?
some of you’re required ports might not open for that specific game or you’re NT restricts itself sometimes, just try restarting you’re router or contact your internet ISP and ask them if everything is running how supposed to run!
I am having the same issue. My NAT is open, all my ports are open as suggested by Xbox Live. Please help!!
Have opened a new thread for this aswell
I have finally found the issue that has been plaguing me for almost a year.
The problem lies within the firmware version of my internet modem, Arris SBG6782 Advanced WiFi Modem.
This has been brought to the attention of Arris by my ISP.
There are many other documented cases of the exact same issues with Xbox Live and this particular modem, finally I don’t feel so alone. 
It is unclear though when the firmware update will be released, no ETA.
As an alternative to waiting, I am going to exchange my SBG6782 for a Cisco DPC3825 Wireless Modem as recommended by my ISP.
Hopefully this will solve the drops and connectivity issues with Xbox live…although I doubt it will fix the holes in the wall of my gaming room.
I went to exchange my modem yesterday, my ISP gave me the Hitron CGNM-2250-SHW. I installed it and played Destiny for a couple of hours on my XB1…not 1 drop from the game or Xbox LIve. Have to try out Halo 4, but I am pretty sure that it will run as it should.