Re: TCP window size bugs and patch (Re: 3 issues)
On 7 Nov, Kevin Gibbs wrote:
> Well I think that all of this functionality will be added to the next
> version but not in this fashion. Thanks for pointing out the send vs. recv
> issue, had not ran accross that so far. I did notice the server sending
> code and had problems with it myself, but TCP at the theoritical
> standpoint is only limited by reciever window and available bandwidth.
>From the iperf & co website :
<http://dast.nlanr.net/Projects/Autobuf_v1.0/autotcp.html>
"To maximize the performance, [the sender should set it's send buffer
size] and the receiver should set its receive buffer size to no less
than the capacity of the TCP pipe. Usually this number is the product of
bandwidth and round-trip-time (bandwidth-delay product)."
This is rather obvious, considering that the sender must keep in its
send buffer all the data not yet acknowledged. When the througput*delay
product is high, the send buffer desesperatly needs to be high.
> I believe this is why there is no setting for max send window size on newer
> Windows TCP implementations.
> As a result it is hard for a client (sender)
> to determine the best window since it has no control over either of the
> above variables.
Well, Iperf seems highly portable, I do not clearly understand why it
should give up some useful features just because Windows does not
support them anymore...? But maybe I did not understand what you said ?
> As far as white space, sorry man. In the next major version there are
> quite a bit of reworking and most previous patches will need tweaking,
"tweaking" is OK, of course. I was thinking about the parts where the
whole indentation has changed between 1.6.2 and 1.6.3 for non-obvious
reasons.
Cheers,
Marc.
--
Mitch Kutzko | mitch --at-- dast.nlanr.net | mitch --at-- ncsa.uiuc.edu | 217-333-1199
http://hobbes.ncsa.uiuc.edu/