Side_1_360

lyst to create and maintain scripts for starting

GenSyn, measurement processes and filtering

and post-processing of trace data. The Designer

is nota runtime system in the sense that pro-

cesses cannot be created, paused/delayed, or

monitored. The only support that will be pro-

vided is a button that enables the uploading

scripts (copying the scripts to the correct

machine), and starting all the scripts. As an

option, there will be a button for deleting an

ongoing experiment, i.e. stop all running pro-

cesses and delete the trace files.

The GenSyn Designer should provide a graphi-

cal user interface for an overview of the

machines that run GenSyn, and give useful sup-

port in distribution of the GenSyn processes and

the measurement probes.

The GenSyn processes require the specification

of a number of parameters, a few of them have

default values but all parameters should be in-

spected before starting an experiment. GenSyn

Designer should provide the necessary support

for the analyst to specify a model for each Gen-

Syn process, the process deployment, and to go

through all parameters related to the specific

model and the machine.

In the case where GenSyn is not only used for

generating background traffic the GenSyn

Designer should provide support for instantia-

tion of measurement probes (e.g. tcpdump or

DAG on specified machines). The probes can be

configured to run various filters with different

packet and flow aggregation or selection,

depending on the measurement objectives

(observation of performance parameters like

throughput, loss, delay, jitter, etc.).

GenSyn Designer has specified a hierarchical

directory structure that stores the input files, e.g.

model types, parameters used, scripts, and the

output files, e.g. trace and end report from Gen-

Syn, raw or aggregated trace data from various

measurement traces, results from post processing

the data, etc.

Figure 23 shows how the first version of the

GUI looks like on the screen. It is possible to

add and remove machines from the layout. Gen-

Syn Designer can save and load these layouts.

Through color encoding the status of specifica-

tion is indicated, e.g. a machine that should run

GenSyn is created, but no model is specified for

that machine, or the model is chosen but start

and stop times for the process not set.

4)It may be noted that the post-processing of packet traces generally is independent of the GenSyn traffic generator. However, currently

the GenSyn DataReporter is tailor-made for this purpose.

Text file

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GenSyn Report Generation

(java)

Scripts

(perl, awk, gnuplot..)

Measurement data

(Packet traces)

Figure 24 Block diagram of post-processing of measurement data

GenSyn

Tg1

GenSyn

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GenSyn

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GenSyn

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Mngmnt

unit

GenSyn

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GenSyn

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GenSyn

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GenSyn

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Storage

unit

GenSyn

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GenSyn

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Network

Figure 25 GenSyn experiment