[Tmrg] Traffic Generators (Harpoon and Tmix)

[Cesar Marcondes]

Dear Sangtae,

I agree w/ Lachlan. I think this extra complexity of application
behavior forcing the pace of TCP transmissions (by waiting read/write
times), just add difficulty to separate the TCP congestion control
behavior alone, for the specific goals of the TCP Test Suite.

Just my 2 cents,
Cesar

On Dec 3, 2007 11:28 AM, Lachlan Andrew <lachlan.andrew at gmail.com> wrote:
> Greetings Sangtae,
>
> On 03/12/2007, SANGTAE HA <sangtae.ha at gmail.com> wrote:
> > We have two compelling traffic generators, Tmix[1] and Harpoon[2], one
> > of them will be used as a common traffic generator for TCP testing.
> > Before deciding which traffic geneator we would go, I list up simple
> > comparisons between them. Feel free to update the table.
> >
> > ----------------------------------------------------------------
> >                   Tmix                 Harpoon
> > ----------------------------------------------------------------
> > TCP/UDP   application-level    application-level
> >                  TCP                     TCP/UDP
> > ----------------------------------------------------------------
> > Model        *(a,b,t) model     inter-arrival time and
> >                                          file size distributions
> > ----------------------------------------------------------------
> > Trace         tcpdump            flow-tool (from routers)
> >                  *manual             *manual
> > ----------------------------------------------------------------
> > Supported   Linux                Linux
> >                   FreeBSD          (FreeBSD)
> >                   NS2
> > ----------------------------------------------------------------
> >
> > *(a,b,t) = (request size, response size, user think time)
> > * "manual" means it supports user-generated vectors or distribution tables
> >
> > Briefly, Tmix supports more platforms (NS2) while Harpoon includes an
> > additional UDP generation.
> > After reading the Tmix paper, it looks *(a,b,t) model can represent
> > user-interactions better than the model based on inter-arrival and
> > file size distributions.
>
> Thanks for checking this out.
>
> I notice that  Tmix  aims to model non-greedy TCP connections.  The
> "think times" are not times between user connections, but pauses
> within a connection.  Will that make it harder for us to collect
> statistics?  If we're measuring things like "file completion time", it
> is much harder to define what a "file" is if it is just part of a
> long-running non-greedy TCP connection.
>
> Tmix is clearly a more general model, but I personally prefer the
> simplicity of considering TCP sources to be greedy.  It simplifies
> distinguishing between the effect of slow-start vs normal operation.
>
> Cheers,
> Lachlan
>
> --
> Lachlan Andrew  Dept of Computer Science, Caltech
> 1200 E California Blvd, Mail Code 256-80, Pasadena CA 91125, USA
> Ph: +1 (626) 395-8820    Fax: +1 (626) 568-3603
> http://netlab.caltech.edu/~lachlan
>
> _______________________________________________
> Tmrg-interest mailing list
> Tmrg-interest at ICSI.Berkeley.EDU
> http://mailman.ICSI.Berkeley.EDU/mailman/listinfo/tmrg-interest
>