Mant thx for the reply..
The ACK number sent during the conn establishment will be 'sequence number of the SYN packets which is used to initiate the connection' + 1
That would actually be true for SYN/ACK packet. In the ACK packet (3rd packet), the sequence number will be equal to the 'sequence number for the SYN in the SYN/ACK packet' + 1
Is there a way to distinguish between this 3rd packet and any other ACK packet during data transfer w/o having to keep track of sequence numbers? Are there other characteristics or options that are set in the former and not in the latter?