Darren VanBuren

Because I don't have a wired connection to my Xbox or a wireless adapter for it, I've used my laptop to bridge my Xbox to the network, and ran Wireshark as well, for the fun of it. Here's what I've discovered: The 360 uses Kerberos to authenticate you on Xbox LIVE (on the PASSPORT.NET domain). Your username is your gamertag. The images on the Dashboard are downloaded over HTTP from, if I remember correctly, the Limelight Networks CDN. Downloads from the marketplace (games, game updates, apps, etc.) come from that same CDN. All over unencypted HTTP. (Man In the Middle fun is certainly possible, but the 360 will only run signed code. You could maybe replace the images on the dash if you're lucky.) Games are locked to communicating for multiplayer using whatever UDP port the Xbox thinks is open. Its' preferred port is 3074 (which is registered as xbox, as shown in the original post). Private and Party Chats also work over the UDP port that the Xbox chose on startup.