Sequence numbers are random. F, FIN- Finish is used during a graceful session close to show that the sender has no more data to send. P, PSH- Push forces data delivery without waiting for buffers to fill. This is used for interactive traffic. The data will also be delivered to the application on the receiving end with out buffering.
Data is sent out of band.
If no acknowledgment has been received for the data in a given segment before the timer expires, then the segment is retransmitted, up to the TcpMaxDataRetransmissions times. The default value for this parameter is 5. The timer for a given segment is doubled after each re-transmission of that segment. The following trace clip shows the re-transmission algorithm for two hosts connected over Ethernet on the same subnet. An FTP file transfer was in progress, when the receiving host was disconnected from the network.