Symptom
Client sends SYN, NAT receives it and create a session with syn-timeout as timeout value
NAT then receives SYN-ACK from server, NAT resets the session timeout values to tcp-timeout (600 sec).
But because the connection to client is slow (2G/3G), before client receives the syn-ack, it re-transmits SYN again.
When NAT receives this retransmitted SYN, it resets the session timeout to syn-timeout values.
Server doesn’t send any SYN-ACK to this retransmitted SYN (expected).
Then client sends ACK, which completes the 3-way handshake.
But NAT timeout values remains at syn-timeout.
