Ethereal-users: Re: RE: RE: [Ethereal-users] Can you help me diagnose a performance problem?
On Fri, 30 Jul 2004 14:07:14 +0200, bleonhardt@xxxxxxxxxxx
<bleonhardt@xxxxxxxxxxx> wrote:
> Hi,
>
> AFAIK,
>
> tcp uses windowing, so not every packet should be acknowledged - of
> course, a ACK of every packet / frame will slow down the connection as
> there's more traffic on the network than usual ..
>
> ... maybe a resize of the window-size could help .. try DrTCP ( just google
> for it ) to change the settings .. then restart your network ( 2k/xp ) or
> restart the pc/notebook.
>
> -Alex
>
> Bruno-Alexander Leonhardt
Right! The TCP receive window size is indicating the other end how
much data (in bytes) can be buffered during the connection. The
sending host can only send that much, before waiting for an ACK, so
this can have a great impact on performance. What strikes me as odd is
the valule for this, in your example. As far as I know, this should be
a multiple of MSS (maximum segment size), so that you do not fragment
fragments, basically.
In any case - a tweak of the above is worth trying (and keeping in
mind the multiple factor I am talking about - which MSS is derived
from the MTU of your underlying infrastructure, and should be seen in
some of the packets (perhaps using windump, if not shown in
ethereal?!?). Though not specifically XP related, start here, or
google for the same terms used in this article:
http://www.jsiinc.com/SUBI/tip4000/rh4015.htm
HTH,
Stef
