[e2e] Some questions about TCP.

[David P. Reed]

On 11/22/2009 02:04 PM, Detlef Bosau wrote:
> 1.: Recently, I was told, however I did not find a reference in some 
> RFC, we had two distinct packet types in TCP:
> - those _with_ payload, which are _data_ _segments_,
> - those _without_ payload, which are _acknowledgements_.
>
Not true.   TCP was designed to piggyback acknowledgements with data.  
Acknowledgements are reflected only as increases in sequence numbers.   
One can think of the arrival of a packet with a sequence number larger 
than any previous sequence number as a "virtual" acknowledgement message.

I am curious who told you that "fact".