TCP three-way handshake

Hello Security guru :o)

I have question regarding how the TCP works? I know that the TCP is a connection oriented protocol and is used to make sure that that packet received in order and at the same time it's a reliable protocol which means if we lost a packet we can detect that based on the TCP sequence number and tell the other side to retransmit the packet again.

TCP is three way-hand shaking, TCP syn packet and other side will reply syn ack and the third phase is the ack. My question is why we need the third phase? what the information we have? Actually, I think if I say hello and the other side is say hello back is enough, why should I need the third step?

Thanks in advance,

Mohammad

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Received on Thu Mar 21 2013 - 06:32:08 ART