Game kit

2 functions:

(1) p2p connectivity:

create an ad-hoc Bluetooth network

(2) in-game voice

use GKSession class

not support first-generation iphone & ipod touch

each peer has a peerID

use displayNameForPeer to get peer's name

GKSessionDelegage: handle connection request

data handler: receive data from peer

3 session mode:

(1)server:

advertise sessionID

GKSessionModeServer

(2)client:

search for sessionID

(3)peer:

advertise sessionID & search for sessionID

GKSessionModePeer