Hi all,
I said in the ops meeting that I'd put together a quick summary
about the RIPE Atlas network probes, so here it is. The documentation
on the RIPE site[1] is pretty good, so I'll keep this relatively
brief[2].
Firstly, 'RIPE Atlas' is an 'Atlas' in the sense that it's a 'mapping'
project, designed to survey the internet (so nothing to do with our
ATLAS[3]), and 'RIPE' as in the European Internet Protocol Registry,
though the project isn't restricted to Europe and there are probes all
round the planet.
The individual probes fulfil a function similar to our PerfSonar boxes,
in that they provide endpoints to run tests from. A key difference is
that the tests are much more basic, and all centred around latency and
functionality, not at all around bandwidth. Accordingly the probe
hardware is much cheaper, being a repurposed TP-Link router[4]. There's
a photo of our one sat on top of (and USB powered from) our PerfSonar
boxes here:
http://www-pnp.physics.ox.ac.uk/~macmahon/ripe_atlas/RIPE-Atlas-probe-UKI-SOUTHGRID-OX-HEP.jpg
As a matter of routine a probe will do various standard measurements,
mostly pings and traceroutes to static targets like the DNS root servers
and dedicated RIPE Atlas Anchor nodes. By hosting a probe, you get to
see the results of its routine measurements which given some idea of
your connectivity to the rest of the internet.
There is also a credits system - hosting a probe accumulates credits for
as long as it's up and working, and you can then spend them on having
the system run your own measurements, either on a one-off or recurring
basis. For example, we had a slight question the other day whether our
web server was unreachable from some places, so I did a quick one-off
test of having a random 300 probes ping it. There's a screenshot of a
graphical view of the results here:
http://www-pnp.physics.ox.ac.uk/~macmahon/ripe_atlas/ripe-atlas-example.png
(it turned out to be fine)
Most of the probes are handed out free of charge, just by asking for one
(which is how we and QMUL got ours). That's possible because of some
organisations sponsoring the costs. The key advantages of being a
sponsoring organisation are[5] that you get to see the routine
measurements from all of the probes you've sponsored, that you get credits
from all the probes you've sponsored (which can be spent on measurements
using any of the probes, yours or not), and the RIPE folks add you to
their publicity, which given that they're one of the main top-level
internet co-ordination organisations, has good impact[6]. I don't know
what it actually costs to sponsor a probe, but I can email the RIPE
contact address and ask if we think we're interested, but taking the
~£30 retail price of the probe as a rough ballpark, spending (say)
£10,000 (which isn't a huge amount in the context of the whole GridPP
project) would get us about three hundred probes to distribute around
our own sites, the rest of the UK academic network, and anywhere else
we wanted to put them. Given that there's a total of just under five
thousand probes currently on the whole system, I suspect we could go
for a smaller batch if we wanted to.
So, to summarise, the RIPE Atlas system has some similarities to
PerfSonar, but in practice it fills a different niche, and they
complement each other well. I think there is some value in our getting
involved, and I think we should seriously look into the possibility of
becoming a sponsor to do so.
Ewan
[1] https://atlas.ripe.net/
[2] I could have been even less brief.
[3] We can only be grateful they didn't call it 'Dirac'
[4] One of these: http://www.amazon.co.uk/TP-Link-TL-MR3020-Portable-Wireless-Router/dp/B00634PLTW
[5] https://atlas.ripe.net/get-involved/become-a-sponsor/
[6] IMPACT!
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