[AusNOG] Group WiFi

[Adrian Chadd]

On Wed, Oct 31, 2007, Stephen Baxter wrote:

> I need to get wireless access for 130+ people for a couple of days. If
> you want to know why then please go to http://2207.ausnog.net :-)   Any
> advice appreciated.

I replied in private to Stephen but I figure I might as well let everyone
else know.

Tony (Anton) Kapela does a lot of wireless stuff for NANOG, the American
network operators group conference; he's put up a few presentations here
and there covering the sorts of things he does to make wireless "work".

His presentation at a recentish nanog on wireless QoS is interesting
and actually gave measurable results:

http://www.nanog.org/mtg-0610/presenter-pdfs/kapela.pdf

There's a realmedia recording of his presentation but I haven't tried it:

http://www.nanog.org/mtg-0610/lightning.html

The basic idea is realising that once you've sorted out the RF engineering
side you still have to deal with a best-effort half-duplex broadcast-mostly
shared infrastructure.

There's a few nifty tips (eg set to drop on max-retry; not deassociate);
also see how CoS maps to physical transmission timing. The "TCP initial" stuff
IIRC is to make sure that TCP connections get a chance to succeed when
there's a whole lot of potentially very large packets clogging the RF
space.

I think he's covered many other aspects including handling roaming, handling
busted wireless clients in laptops (vista's is fun!), RF design tips as
well as the obvious stuff.

I'm trying to get references to some of his other presentations and
see if I can't put them all up somewhere which can benefit everyone.

(Note: I've deployed QoS on Cisco APs and measured "stuff", but for VoIP
 and video streaming in an office environment, not for a conference.)



Adrian