[Netalyzr] New features!

Christian Kreibich christian at icir.org
Wed Feb 29 17:09:50 PST 2012

Hi all,

We have just released a substantial Netalyzr update. First and foremost,
we've made Netalyzr a whole lot faster. After analyzing the
test durations experienced by our users, we increased parallelization in
test executions and optimized a number of timeouts, all with the goal of
reducing execution time. Netalyzr now runs approximately twice as fast
and a session typically completes in under two minutes.

We have also improved the level of control you have over the amount of
information displayed on the test results page. You can now expand and
collapse details of individual tests, instead of entire test categories.
In the initial results display, this ability lets us show details only
for tests that exhibited irregularities or problems, while keeping all
other results collapsed. See the help page for more information:


Several users reported that Netalyzr's bandwidth test at times crashes
their DSL modems, causing a temporary loss of network connectivity. This
outage could cause Netalyzr sessions to stall at the result upload
stage. We now attempt result uploads several times while waiting for
connectivity to resume. You may have noticed that Netalyzr tries to use
the UPnP protocol to identify the model and manufacturer of your gateway
device. In the future, this information, combined with tracking outages
induced by bandwidth tests, will allow us to identify particularly
fragile devices.

For researchers we now provide better ways to label Netalyzr sessions
and obtain the resulting set of result data. Netalyzr has long provided
a command-line interface, but no convenient way to obtain test results
for subsequent processing. In addition to the regular HTML summary we
now also provide the session results in JSON format. To obtain a
session's results in JSON, use this URL schema:

  http://netalyzr.icsi.berkeley.edu/json/id=[session ID]

For example, here's our demo session in JSON:


Note that we're still in the process of improving the details reported
for individual tests. We'd love to hear your feedback and suggestions.

If you're a researcher providing customized ways for people to run
Netalyzr, you can now arrange to have all resulting sessions
automatically tagged with a string identifying your experiment and
retrieve the list of resulting sessions in near-real-time, likewise in
JSON format. If you're interested in this feature, please contact us.

As we're approaching the 500,000 session mark, we'd once again like to
thank our users for their ongoing support and use of the Netalyzr
service. We couldn't do this without you!

Christian, Nick & Vern

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