[e2e] Are Packet Trains / Packet Bursts a Problem in TCP?
shemminger at osdl.org
Tue Sep 26 14:08:56 PDT 2006
On Tue, 26 Sep 2006 14:39:34 -0400
"David P. Reed" <dpreed at reed.com> wrote:
> Fred Baker wrote:
> > As Bob says, systems often have fairly obnoxious timing signals
> > available to them. One might hope that this could get fixed :-(
> Not that it should matter, but I write network code every day for XP,
> OSX and Linux. Perhaps the grandees who manage are still living in past
> The days when end-system clocks had really lousy resolution are gone,
> gone, gone. While getting resolution below a millisecond is still not
> always possible, all of these platforms, when running on 500 MHz
> processors or better, do just fine with minimal overhead when running
> activities that need to be scheduled with millisecondish granularities.
You must live in a world without power management and SMP.
The number of systems that can't get a high resolution synchronized
and stable clock seems to be increasing not decreasing!
> Of course it's a little harder to do this in user space, one needs to
> know how to manage user space thread priorities. But in the kernel,
> where networking is usually done, it's no problem. And in user space
> it's not actually hard, you just need to RTFM.
Stephen Hemminger <shemminger at osdl.org>
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