Wireshark · Wireshark-users: Re: [Wireshark-users] PCI of a TCP-segment

[Stephen Fisher <steve@xxxxxxxxxxxxxxxxxx>]

On Tue, Oct 11, 2011 at 08:20:04PM +0100, Lisi wrote:

> I didn't.  But that is verbatim what my tutor said, and I can't make 
> head or tail of it.  Control bits are the bits in "the PCI of a 
> TCP-segment".

Well, now I'm curious, so let's break it down.  What was the context of 
the discussion?  I assume by "control bits," he meant what Wireshark 
calls the "Flags" which are Nonce, Congestion Window Reduced, ecn-echo, 
URGent, ACKnowledgement, PuSH, reset, SYNchronize and FINish bits (and a 
few reserved for future use).  The only other things in a TCP segment 
are shown here:

http://www.networksorcery.com/enp/protocol/tcp.htm

(scroll down to the TCP header chart)