Re: [ns] Tracing TCP

["Nikolaos Katsarakis Austauschstud. (M. Schweigel)" <katsarak@ifn.et.tu-dresden.de>]

Thank you very much for your answer.

My question was not very clear. I wanted to distinguish retransmitted tcp packets in general. In the
trace file both the normal and retransmitted packets look alike. The retransmitted packets have an
---A--- flag, but this is not a good method to distinguish them, as there are many normal packets
with the same flag.

Bye

Nikos

Dimitris Velenis wrote:

> I suppose you can look in the trace file for 3 (or whatever value you have set
> numdupacks_ to) duplicate ACKs requesting the retransmitted segment. If you
> find those acks in the trace file then the retransmission was due to Fast Retransmit.
> If not then you had a retransmission timer timout.
>
> Dimitris.
>
> On Fri, Jul 13, 2001 at 09:19:45PM +0200, Nikolaos Katsarakis Austauschstud. (M. Schweigel) wrote:
> > Dear ns-users
> >
> > Is there any way to distinguish in the ns track file the retransmitions
> > due to timeout of retransmission timer of TCP?
> >
> > I tried to enable tracing TCP headers, by changing ns-default.tcl and
> > recompiling, but I only got zeros in the extra fields. I am using
> > one-way TCP, are the TCP headers only useful for FullTCP?
> >
> > Thank you very much?
> >
> > Nikos
>
> --
> Dimitris Velenis                              <dbelen@netmode.ece.ntua.gr>
> Network Management & Optimal Design Lab
> National Technical University of Athens