When i go into the matchmaking lobby it says that the servers are unavailable at this time. It also does not load my player model. Are the servers really down? Cause i havent seen any other posts about this in the forums…
It must just be you cause I’m the a lobby ready to start matchmaking. Maybe try starting up the game again
The past few days, I’ve experienced lag and other, similar and random, issues. I expect them to be fixed within the next few days. 
I was just playing online about 5 minutes ago.
Probably just a Halo Glitch where you sign out, then immediately sign right back in, and show up as… nobody… then your profile shows up. As far as the ‘server unavailable’ issue, check your rank (and Spartan) when you sign in.
Bad servers and bad connections abound.
I don’t know why this game doesn’t host cycle on solid redbar connections when people are lagging out. At least Halo 3 normally caught on while Reach stays the course with an awful host until he/she hopefully quits putting everyone out of their misery.