Why PyCon 2010's Conference Wi-Fi Didn't Melt Down

jafo writes "There's been a lot of teeth gnashing going on recently about broken wireless at conferences. We just wrapped up PyCon 2010, with around 600 (out of 1,000) attendees simultaneously accessing the volunteer-run network, and response has been fairly positive. 2.4GHz (802.11b/g) continues to be problematic, but most users were on 5.2GHz (using 802.11n) and associating at 130mbps, with a 100mbps link to the net (though after the fact we found that 35mbps would have sufficed). My PyCon 2010 wrap-up reveals all the secrets of how we did it, including pretty bandwidth and user graphs."

Comments

On units and their prefixes

[Bromskloss]

Editors, please do your job before you accept a story - that's an easy way to make Slashdot much better. In this particular story, it would have been easy - no research required. As I'm sure almost everyone here knows, m != M. Also, what is wrong with "b/s" instead of "bps"? (Also, how do I write non-ASCII characters here?)

Re:On units and their prefixes

[Rogerborg]

Just FYI, the "job" of a Slashdot "editor" involves scoring Rob Malda some weed when you were at community college together, writing a very small shell script to post every 25th story submission, then scarfing beer and cheetos while playing in the Furry zone of Second Life for the rest of your "career".

Mod hints: -1 Troll, +1 Informative, +1 Insightful

Re:On units and their prefixes

[trapnest]

I suppose that would be really important if the summery were not in english.

Re:On units and their prefixes

[TeknoHog]

Where does 'b' mean byte? I have never seen that in literature, and the only times I've seen it written in conversations it can generally be attributed to laziness, often accompanied by a lack of capitalization at all.

I once filed a bug about an application that used kb/s to denote kilobytes per second. It was changed to kB/s for a while, but pretty soon reverted to the lazy form. At least they used / though :)

Here's a nice example from the manpage of tc, part of iproute2:

Bandwidths or rates can be specified in:

kbps Kilobytes per second

mbps Megabytes per second

kbit Kilobits per second

mbit Megabits per second

bps or a bare number
Bytes per second

Amounts of data can be specified in:

kb or k
Kilobytes

mb or m
Megabytes

mbit Megabits

kbit Kilobits

b or a bare number
Bytes.

Well, perhaps this is so that you can write your command line in all lowercase. In other words, laziness.

Re:On units and their prefixes

[AK Marc]

Agreed, perhaps this is only a matter of style. As a scientist I would never write something like mps for metres/second, even though the spoken unit is "metres per second". It would look silly and unprofessional, and I've already explained the point about mathematical symbols elsewhere in this thread.

In the US, mpg, mph and bps are used almost exclusively. They aren't "scientific" or "mathematical" expressions, but vernacular that took over all uses, regular, technical, and such. If you have a problem with that, it can't be fixed by what "should" be done for the scientific reasons, because if that worked, the "m" in mpg and mph wouldn't be used anyway. And it's not like a bit is an SI unit, so it's failing to fall under that standard regardless of "per" being used.

Test, you idiot

[cerberusss]

FTFA:

Crimping your own RJ45 should be avoided

Author should have said "testing should NOT be avoided".

I hate it when people say such things. A cable tester costs $15 and you neglected testing. Don't say "crimping your own RJ45 should be avoided". That's blaming someone else for your idiocy.

Re:Test, you idiot

[ZorinLynx]

As someone who crimps our own cables at work, full agreement here.

I rarely have problems with self-crimped cables. Another group that crimped its own cables here was having all sorts of problems. Why? They were doing a lousy job of it.

Test every cable. Make sure the conductor order is correct. Make sure the conductors go all the way into the connector to the stop at the end. USE THE RIGHT CRIMPER. Some cheap crimpers don't crimp all the crimp points and leave the wires less mechanically supported. The crimp point that's usually missed is the one just behind the metal contacts, which is one of the most critical points of all.

And most importantly, make sure you are using the correct plug ends for the cable you are using! Stranded and solid conductor cables require different types of plug. Using the wrong one nets you a connection that works now but won't work later.

Re:I avoid conference WiFi's...

[hitmark]

probably picks up a pay-as-you-go at the airport of whatever nation he happens to visit.

Re:i feel his pain

[v1]

Saves the worry, AND saves the fingers. Mine start cramping at about the 25th end when I'm in a hurry.

I can't believe that they seriously planned to crimp things by hand. I can understand for the occasional single long haul runs, but they made it sound like they were doing many dozens of crimps, and that's just plain silly. The money you save in not paying for molded cables you lose in time and hassle created by bad crimps.

Did you catch the other hilarious minor detail? they only had one crimping tool! That's how to turn fail into epic fail. And they PLANNED it this way... wow.

Re:Nothing to see here, move along

[Anonymous Coward]

If he's so great why did you try to replace him?

Re:Learning is knowledge

[RzUpAnmsCwrds]

Actually knowing a bit about jafo and the setup at PyCon, I can tell you exactly what's wrong with your idea: money.

The IEEE/ACM SuperComputing trade show's network (SCinet) does exactly what you say. They also have 10,000 attendees, over 50 people working on the network, a decent budget, and a ton of donated gear and bandwidth.

PyCon (and jafo) don't have $100k to spend on the network. That means that you have to make do with low-cost commodity hardware. The fact that the network can stay up and deliver acceptable quality of service is a testament to jafo's experience.

Building a conference wireless network that works when you buy gear designed for that purpose isn't particularly notable.
Building a conference wireless network that fails miserably with consumer-level gear isn't particularly notable.

Building a conference wireless network that works with consumer-level gear on a shoestring budget *is* notable.