[1st-mile-nm] Subject:Grappa Wireless Internet

[John Osmon]

I don't mean to hijack this thread, but I think it is important
for folks on this list to have a good grounding on what works
and what doesn't.  Wireless is a legitimate 1st mile technology -- it
is easier to deploy than fiber and/or copper, but has unique 
characteristics...


On Mon, Oct 27, 2008 at 06:49:41PM -0600, Bob Knight wrote:
[...]
> I'd be *very* disappointed if I were a paying customer getting the 
> "performance" you're getting. Sounds like you're paying for a learning 
> curve.

In general, WISP customers have to suffer through their provider
learning the following:
  - LOS/Fresnel zone issues (how to make the wireless links work)
  - Interference issues (concentrate on *your* S/N, not what channel 
    other folks are using)
  - basic networking issues (route early, route often - briding does
    not scale)
  - advanced networking issues (wireless is usually constrained by 
    packets per second, and *not* bandwidth) 

It's a lot of things to take in when you're starting out, so a lot
of WISPs can't climb over the learning curve(s).  (I weep for the 
customers of some WISPs.)


> > 5. No system could demonstrate good symmetrical performance average 
> > was ( performance quoted to actual = Down 60% --- Up 20 - 30% )
> The very nature of 802.11 makes symmetric performance problematic in 
> some situations. However, I just pulled 8 megabits upstream from the 
> WRAP on my roof to one of our servers. YMMV.

The nature of half-duplex connections make this a sticky subject all
around.  Capture effects and other issues dictate that you will
eventually need to move to full duplex as contention issues increase.
If the WISP has multiple aggregation towers, the backhaul links will
need to move that direction first.


> > 6. Security issues were noted on all systems and interception of both 
> > down and up was fairly easy with open source products
> Not a surprise. WEP is a joke, WPA isn't much better if one has enough 
> iv's. That's why I believe in ssh, https and VPN's for stuff I don't 
> want prying eyes to see.

End-to-end encryption is *always* the right answer.  Your best friends
should be ssh/https/VPN/TLS. 



> We do monitor, and we are putting in place some sophisticated traffic 
> shaping on a transparent bridge as an anticipatory measure. However, our 
> DS-3 is being used at no more than 20% capacity down and much less up. 
> Misbehaving torrents are generally dealt with through education and, 
> once educated, members tend to be very well-behaved.

Monitoring is the key.  Tracking and trending some key stats will let
you *know* when you need to tune/tweak things.