Network Latency Measurements

Jim Gettys jg at
Wed Dec 5 15:16:41 UTC 2012

On Tue, Dec 4, 2012 at 4:05 PM, Tal Mizrahi <talmi at> wrote:

> Hi,
> We are looking for publicly available statistics of network latency
> measurements taken in large networks.
> For example, there is FCC's measurements (
> ).
> However, we are looking for something more detailed that can show a large
> number of latency measurements taken periodically (preferably with as small
> a period as possible).
> Here are the datasets I'm aware of:

ICSI Netalyzr
The FCC measurements

None of them, to my knowledge, take latency measurements "periodically".

I watched a nice demo at a talk about Mlabs a couple weeks ago of the
ability to query their data set and plot the results.  They happened to
plot a million or so latency samples (and they have when those samples were

Just don't throw out the "can't possibly happen" outliers; bufferbloat is
bad enough (if you look at the Netalyzr scatterplots you can find here
see why...).  Unfortunately, latencies measured in *seconds* are not only
possible, but not uncommon (e.g. my brother's DSL service has > 3 seconds
of buffering in each direction under load).

                         - Jim

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