TCP
Analysis - Section 7: Data & Quick Summary
Introduction
Finally,
the last page of our incredible TCP Analysis. As
most of you would expect, this section is dedicated
to the DATA, which is also the reason all the
previous pages exist!
The Data
The
following diagram may have been tiresome, however,
it will be displayed one final time to note the data
portion of the packet:
Your
knowledge regarding the procedure followed when the
above packet arrives to its destination is assumed.
However, a summary is given below to refresh our
understanding in order to avoid confusion.
When the
above packet arrives at the receiver, a
decapsulation process is required in order to remove
each OSI layer's overhead and pass the Data portion
to the application that's waiting for it. As such,
when the packet is received in full by the network
card, it is given to the 2nd OSI layer (Datalink)
which, after performing a quick check on the packet
for errors, it will strip the overhead associated
with that layer, meaning the
yellow blocks
will be removed.
The
remaining portion, that is, the
IP header,
TCP header and
Data,
now called an IP Datagram, will be passed to the 3rd
OSI layer (Network) where another check will be
performed and if found to be error free, the
IP header will
be stripped and the rest (now called a Segment) is
passed to the 4th OSI layer.
The TCP
protocol (4th OSI layer) will accept the segment and
perform its own error check on the segment. Assuming
it is found error free, the TCP header is stripped
off and remaining data is given to the upper layers
eventually arriving at the application waiting for
it.
Summary
Our
in-depth analysis of the the TCP protocol has
reached its conclusion. After reading all these
pages, we are sure you have a much better
understanding regarding the TCP protocol's purpose
and process, and you are able to really appreciate
its functions.
We hope
you have enjoyed our analysis and we're sure you
will be back for more!
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