networking scenarios

[Sameer Verma]

Dafydd Harries wrote:
> This is something which was not completely clear to me until I talked to Wad
> about it the other day, and I think other people might find it useful. It
> should probably go on the wiki (assuming it isn't already there somewhere). I'd
> like some feedback about where it belongs. The closest thing I've found is this
> page:
>
>   http://wiki.laptop.org/go/Scenario_taxonomy
>
>   

The wiki page you refer to was my attempt (at least the first cut) at 
getting some kind of a scenario taxonomy going. The idea was that if we 
could look at different combinations of grid availability and backhaul 
availability, we could look at the landscape of scenarios and solutions 
that may work for one or more scenarios. For example, a low powered (can 
run off a battery) server unit will work for all situations with 
unreliable or non-existent grid power, but for a school that has 
reliable power (say, Birmingham, AL), setting up a more powerful server 
would be possible. The same goes for backhaul. I didn't want to start 
with too fine grained a scale, so I didn't specify bandwidth, latency, 
etc. and leave the scales at a more qualitative low/medium/high level.

> Any errors are my own.
>
> There are four networking scenarios:
>
>  - simple mesh
>    - no access point
>    - no school server
>    - we are currently aiming to support up to 15 laptops in this case
>  - simple WiFi
>    - access points
>      - which tend not to handle multicast very well (1Mbit/s peak)
>    - no school server
>    - this is what G1G1 laptops will tend to encounter
>    - typically in the developed world
>  - school mesh
>    - no access point
>    - school server with Jabber server
>  - school WiFi
>    - access points
>    - school server with Jabber server
>      - only one server at a time
>    - this is what is deployed in Peru
>
>   

Assuming that a matrix such as the one at the bottom of the wiki page 
covers most of what we are looking for, each scenario would lead to a 
set of technologies (hardware, software, network) for that scenario. We 
briefly talked about this at the first phone conference for the server 
development.

> Our current priority in terms of collaboration is to improve supprt for the
> fourth case, as this is the situation most of our existing laptops are
> deployed in, and it's likely that upcoming deployments will be similar. Our
> secondary priority is improving support for the second case, as this is what
> will tend happen when laptops are taken home from school.
>
>   

Sameer

-- 
Dr. Sameer Verma, Ph.D.
Associate Professor of Information Systems
San Francisco State University
San Francisco CA 94132 USA
http://verma.sfsu.edu/
http://opensource.sfsu.edu/