We are recently testing Webrtc with TURN over TCP and observed that, often it easily reach 5seconds timeout for STUN ping response wait time and then marking the transport channel as timeout. The same network works fine with TURN over UDP.
I changed CONNECTION_WRITE_CONNECT_TIMEOUT and CONNECTION_WRITE_CONNECT_FAILURES to 10s in Connection::UpdateState for TurnPort and TCPPort, it seems working fine.
It would be nice to know your experiences on TURN over TCP timeouts and any plans on adding this change to Webrtc.