The connection establishment process actually accomplishes
several things as it creates a connection suitable for data
exchange:
o	Contact and Communication: The client and server make
contact with each other and establish communication by
sending each other messages. The server usually doesn’t even
know what client it will be talking to before this point, so
it discovers this during connection establishment. 
o	Sequence Number Synchronization: Each device lets the
other know what initial sequence number it wants to use for
its first transmission. 
o	Parameter Exchange: Certain parameters that control the
operation of the TCP connection are exchanged by the two
devices.