Big Temporary Networks

Måns Nilsson mansaxel at besserwisser.org
Thu Sep 13 20:32:30 UTC 2012


Subject: RE: Big Temporary Networks Date: Thu, Sep 13, 2012 at 04:05:41PM +0000 Quoting Dylan Bouterse (dylan at corp.power1.com):
 
> I'm not sure if this is obvious for this list or not, but with your WiFi nodes, a good practice for that kind of density is more nodes, lower power. Keep the client connection load per AP as low as possible to improve overall performance. Jacking up the power in a small area like that will just step on the adjacent APs and cause issues.

++; 

An enterprisey AP flock that perhaps even can talk to eachother about
power levels is a must.

At all possible cost, avoid login or encryption for the wireless. Captive
portals suck, especially if they try to be clever and keep an eye on the
link-state to each client. Tablets and smartphones turn their radios off
to conserve battery, and that means having to login all the time.

While things have become much better, doing 802.1x on conference wireless
probably is a bit daring. OTOH eduroam does it all over Europe. 

Get lots of IP addresses. A /16 probably still can be borrowed for this
kind of event. I know RIPE had rules and addresses for this kind of use
a couple years ago, at least.

And get v6. 

Do not NAT. When all those people want to do social networking to the same
furry BBS while also frequenting three social app sites simultaneously
you are going to get Issues if you NAT. So don't. (Keep in mind that the
5-tuple for each TCP connection more often will become a 3-tuple if the
demographic of the user base is skewed towards a focus group and NAT is
in use. )

Lots of IP adresses will also enable you to set sensible DHCP lease
times on the failover-connected (because they are, right?) DHCP
servers. Nothing is so detrimental to connectivity experience as lost
leases from either crashed DHCP servers or short lease times.  
Be very thorough and careful in setting DHCP up. It'll pay off. 

Have DNS resolvers locally. Unbound is good. As is BIND. 

It might be a good idea to have reverse DNS delegation set up,
perhaps via the BIND $GENERATE directive; just something like
wireless-node-47-11.world.con will do. 

Make sure that the whois contacts for the address block are proper. 

Try setting some monitoring up; it is good to be able to keep an eye on
client count per AP etc. This is also much easier if the wireless solution
is enterprisey.

-- 
Måns Nilsson     primary/secondary/besserwisser/machina
MN-1334-RIPE                             +46 705 989668
The entire CHINESE WOMEN'S VOLLEYBALL TEAM all share ONE personality --
and have since BIRTH!!
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