There are some obvious and consistent server problems going on right now. I’ve been DC’d from at least 4 ranked Arena games in the last hour or two. Normally, this would be fine with me, but this has happened multiple times in the past few months, and even more since the game was released, which I find unacceptable and inexcusable. 343 Industries, please address your server stability issues. I am seriously considering trading my copy in, which I don’t really want to do because I love Halo so much, but this is getting absolutely ridiculous.
Try going wired, this game is very unstable on wifi. The servers need work. I wish they would address this.
Already on wired 
If you are already wired and have your NAT set to Open the only other thing to try is opening ports in your router or enable the DMZ mode in your router for your xbox… Remember if you do the DMZ route only do it to your xbox nothing else. The DMZ mode is not secure and bypasses any firewall you have in your router… Good luck… We all need it with this game/servers…
Zippy…