Xbox live is mainly built on a custom VPN protocol. The only part they don't encrypt is their chat in order to allow "lawful intercept". This is a custom prot

Xbox live is mainly built on a custom VPN protocol. The only part they don't encrypt is their chat in order to allow "lawful intercept". This is a custom protocol to allow this at the level of TCP and UDP called VDP so that you can't really forget to flip the 'don't encrypt' flag for surveillance. They also switched Skype to using a centralized system for signalling when they acquired it. It's still decentralized at the protocol level, simply Microsoft whitelists their own nodes as supernodes.