because of multithreaded's uncertainty, sometimes the onOpen method is invoked before onICEServers: method in APPRTCAppDelegate, then the peerConnection won't crate offer sdp successfully, beacuse the peerConnection is NULL at that time.
How to slove it?
In APPRTCAppClient, initialize GAEChannelClient in updateICEServers:withTurnServer: method rather in connectionDidFinishLoading: method
because of multithreaded's uncertainty, sometimes the onOpen method is invoked before onICEServers: method in APPRTCAppDelegate, then the peerConnection won't crate offer sdp successfully, beacuse the peerConnection is NULL at that time.
How to slove it? In APPRTCAppClient, initialize GAEChannelClient in updateICEServers:withTurnServer: method rather in connectionDidFinishLoading: method