[Tmrg] Traffic Generators (Harpoon and Tmix)

[Michele Weigle]

There is work currently ongoing to implement the three simulators
Tmix, Harpoon, and Swing (from Amin Vahdat's group at UCSD,
http://www.cs.ucsd.edu/~kvishwanath/Swing/) in ns-2, GTNetS, and the
upcoming ns-3.  So far, we have Tmix implemented in ns-2 and GTNetS.
We're currently in the process of validating the GTNetS implementation
and preparing both versions for release.

In addition to this simulation-based work, collaborators at UNC will
be building a framework for Linux and FreeBSD in which any of these
three simulators could be used in testbed experiments.  See
http://nsf.gov/awardsearch/showAward.do?AwardNumber=0709081

Also, I believe that the Tmix model can be extended to support UDP
traffic, but I'm not sure if that's been implemented yet.

Regarding the pauses that are part of the Tmix model, these pauses are
used to represent the time between complete application data units
(ADUs), which are essentially files.  If you were modeling HTTP
connections, for example, the 'a's would be requests and 'b's would be
responses.  You are right that Tmix can model persistent HTTP
connections, where there are pauses in a single connection.  If you
wanted to have a set of long-lived greedy TCP flows, you could
construct connection vectors to give you such behavior.

-Michele

On Dec 3, 2007, at 1:52 PM, SANGTAE HA wrote:
Hi all,

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.

Welcome your comments.

Sangtae

[1] M. Weigle, P. Adurthi, F. Hernandez-Campos, K. Jeffay and F. D.
Smith, Tmix: A Tool for Generating Realistic TCP Application Workloads
in ns-2, CCR, July 2006
[2] J. Sommers and P. Barford, Self-Configuring Network Traffic
Generation, IMC 2004.
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--
Michele Weigle
Assistant Professor
Department of Computer Science
Old Dominion University
Norfolk, VA 23539
mweigle at cs.odu.edu
http://www.cs.odu.edu/~mweigle
(757) 683-6001 ext. 5050