Hi, syn, ack and so on are packets exchanged in a TCP session between peers.Ack is a acknowledgment and syn is for synchronization.
You can find at the web a lot of tutorial about this, for example:
http://www.ssfnet.org/Exchange/tcp/tcpTutorialNotes.html
But, for a good knowledge about networks I'll read a good book about networks.
Regards.
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