[GLLUG] Mesh Networks

[Richard Houser]

Satelite and any long range wireless (ex. Ham radio) would be
unaffected for outside links, though possibly text only speeds).
Also, standard 802.11 stuff is known to go for miles point to point
with a decent homemade antenna.  You only need to link close enough to
an area so people can physically get near a node (ex. sneakernet or
avian carrier).

Smtp and xmpp are already peer to peer, and could handle such a
network with minimal fus, plus there's always good old uucp and
fidonet if you have intermittent links.  Nobody really needs live web
access, as there are already smtp to www gateways in use since the bbs
days.

On 3/19/11, Charles Ulrich <charles at bityard.net> wrote:
> On Fri, Mar 18, 2011 at 10:35 PM, Chick Tower <c.e.tower at gmail.com> wrote:
>> When Egypt was cut off from the internet, I remember reading that people
>> could set up mesh networks with their PCs and still communicate that way.
>>  However, I didn't see _how_ they would communicate.  Would they use IM,
>> IRC, e-mail, or what?  Does anyone know?
>
> I guess it depends on whether there are points on the mesh that act as
> Internet gateways. If so, and if those are reliable enough, then they
> just continue to use Internet services (Twitter, etc) as usual.
>
> If there are no Internet gateways on the mesh, then there are several
> problems. The biggest being that the only realistic option for
> semi-reliable communication would be peer-to-peer applications.
> Unfortunately, there aren't many P2P replacements for common
> Internet-style applications. We have bittorrent for larger chunks of
> isolated content, but nothing that I know of can replace web browsing,
> email, and instant messaging in a P2P fashion.
>
> The other issue is that wifi signals are, by design, pretty weak. Even
> in a densely-populated area, there would be many small clusters of a
> few stations which can talk to each other, but none are close enough
> to a neighboring cluster to join the networks together. Or, the few
> that are would get overwhelmed with traffic. Each station needs to
> have a radio that can reach dozens to hundreds of other stations
> because the only way to compensate for the massive instability in a
> mesh network is by massive redundancy and smart algorithms which can
> pick the best (say) five peers out of a hundred. Not even
> well-developed countries like the U.S. have mass-market wireless
> equipment that can do this, and we definitely don't have the radio
> spectrum for such devices to operate in.
>
>> Would this be something we could try at a meeting, to set up our own
>> little
>> mesh network and use it?  What would we need, other than our PCs, wireless
>> cards, and the standard software that comes in a Linux distro?
>
> There is apparently software out there to deploy and manage mesh
> networks (say, if you have a lot of property and have to cover it with
> a bunch of access points), but we could probably get a sense for what
> a real-world "guerilla" mesh network would look like just by
> disassociating from the Gone Wired AP and setting up an ad-hoc wifi
> network. (Spoiler: it will be a lot like plugging our laptops into an
> ethernet switch with no uplink.)
>
> Charles
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