[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Going back in time?
Have you modified anything in NS code?
I've had this problem becouse of incorrect calls to Scheduler::schedule.
If something schedule an event with a time already gone (minus than
current time of the scheduler), the Scheduler::dispatch will generate
that message.
I've solved my problems debugging with a breakpoint in scheduler.cc line
99 ( fprintf(stderr, "ns: scheduler going backwards in time from %f to
%f.\n", clock_, t); ), and than with backtrace to find the incorrect
scheduling.
Hope this helps,
Max
--
Massimo Pegorer, student
Dipartimento di Elettronica e Informatica
Universita' degli Studi di Padova
Padova - ITALIA
Deepesh Chouhan wrote:
>
> hi,
>
> But i am sending ARP-like packets along with TCP packets ..
> so do they also create problems ?
>
> Deepesh
>
> On Mon, 26 Jul 1999 [email protected] wrote:
>
> > hi,
> > i have seen this thing happen. one of the cases is when you attach
> > a member of the /Application/Traffic/.. to TCP sources. This is
> > because TCP has its own scheduling mechanism based on the cwnd and
> > other parameters and trying to force it to send packets according
> > to times generated by traffic generators from /Application/Traffic/..
> > may violate some restrictions.
> >
> > the bottomline is this may happen if you are attaching a traffic
> > generator to TCP sources. hope this helps,
> >
> > biplab
> >
> >
> >
> > On Mon, 26 Jul 1999, Deepesh Chouhan wrote:
> >
> > > hi,
> > > even i got this error ..
> > >
> > > Please, can somebody help us out.
> > >
> > > Deepesh
> > >
> > >
> > > On Mon, 26 Jul 1999, Daniel Friedman wrote:
> > >
> > > > What are some general or specific reasons to diagnose why NS might
> > > > go backwards in time? As, for example, when the simulator gives a
> > > > message like this one:
> > > >
> > > > ns: scheduler going backwards in time from 324.400754 to 324.349757.
> > > >
> > > > Thoughts?
> > > >
> > > > Thanks,
> > > > --daniel
> > > >
> > > > ---------------------------------------------------------------------------
> > > > Daniel Friedman [email protected] http://www.isr.umd.edu/~danielf
> > > >
> > > >
> > >
> > >
> >
> >