Tuesday, July 14, 2009

Our setup

So some OLPC people have asked us to describe our technical setup. At the moment, since our server is not working, we are using a switch to rout the internet to the different routers. The school is setup like this:

with the headmasters office in grey. The blue spot is where the DSL modem, (A D-Link DSL 2640) is located, as well as the switch and the server. The internet setup there is as follows: telephone line->modem->switch->out to routers, since the server is not yet working. When the server is setup, the internet should flow like: telephone line->modem->server->switch->out to routers. The red dots are the routers, and the green lines are the ethernet cables.

From the headmasters office, we drilled a hole through the wall, stuck some ethernet cable in a plastic hose and buried it going out to the two buildings. Once it gets to the buildings, we've enclosed the naked ethernet cable in a conduit like:

The cable comes in at the bottom and terminates at the top like:

In addition, there is an electrical outlet for the router there too:
In that picture, the router is not wired up, here it is:

Because of the different configurations of the rooms, all the different shelves are in different places, for example in another room, the shelf is closer to the floor:

You might have noticed before that we have two ethernet jacks in our conduit, with cable coming out of both of them. That's because our routers are daisy-chained (connected) to each other, but not directly. If they were connected directly, the cable might have broken/torn the router itself if it was ripped out of the router, and we would have to buy a lot more cable to fix it. Instead, the internet comes in through one jack in the conduit, then a short cable comes from the router and goes back to the conduit, and then we have a cable on the wall going to the other router in that building. See this picture:

The router in the picture is closer to the headmasters building. The other routers don't need that second short cable because they're not connected to another router down the line.

Right now all the routers have the same SSID (network name), and the hope is that whatever router you are closest to your computer will connect to. We turned down the wireless broadcasting strength in DD-WRT to 10 mW (from 28 normally) so that we wouldn't be broadcasting outside school walls:

Currently, we've been having some problems with the internet slowing down and we're not sure if it's related to the fact that we're using the internet more or if it's because there are 5 wireless routers (the modem is also sending out a wireless signal because it's a combo dsl modem+switch+wireless access point) and even though we've put them on different channels (1, 6, and 11) there are two that are interfering with the others. We're going to do some testing once we get the server and disconnect a router + turn off the wireless of the modem to see if three routers + the server can handle the load of a lot of laptops. We're going to try to connect a lot of laptops to one specific router and see what happens, to see if the server handles all the ejabbered requests properly. Maybe the internet will be a little better once we have the server b/c we'll have the SQUID internet caching service working.

In other news, today was our second day of teacher training and it went quite well. After diving into a learning activity the first day, we backed up and taught the computer starting from the basics. We drew the keyboard on the board:

and had Devon explain what all the buttons and ports were used for. Next, Devon explained the entire user interface - Home, Group, Neighborhood, Journal, and Frame. We practiced sharing activities and as usual, sometimes it didn't work. I think this was a good thing because it shows the teachers that there are going to be problems with the laptops.

As to be expected, there are some teachers who are really excellent and who have used computers before, and there are some teachers who lag behind. The main barriers are the fact that the keyboard and touchpad are small and unforgiving to larger (i.e. adult) hands, and that we don't speak the language. My french is getting better, but it's still hard to understand when people ask me questions out of the blue. It's much easier for me to understand when I ask them a question and expect a certain response.

It's really nice to finally dive into some real work here! In the coming weeks, we're going to be constructing charging cabinets for the XO, finishing up teacher training, and starting to work with the kids. Also, we ordered 10 more XO's from OLPC to completely saturate the top 5 grades.

By the way, the top 5 grades have this student distribution:
Grade - # students - appx age - teacher name
CP - 49 ~8 - Jean-Claude Sagna
CE - 46 ~9 - Francoise Thiaw
CE2 - 39 ~10 - Mme Elizabeth
CM1 - 33 ~11 - Helene Diagne
CM2 - 37 ~12 - Pierre Khar Tine - also the headmaster

There is a lowest grade, CI, but we don't have enough computers to cover it. The incoming class from the preschool is about 30 kids and it would be too much. In any event, that adds up to 204 kids - however we have 5 teachers, plus the technology director of catholic schools (Elizabeth) who we are giving a laptop to, which brings our grand total of laptops needed to 210 - which is why we need to buy 10 more!

Fortunately, because the UMiami team no longer needs their solar panels (they had ordered 50 in the event that they were going to Kankossa, Mauritania), they are sending the panels back and we are getting credited for those panels (~$1,200). Which means that half the cost of the laptops ($200* 10 laptops + $400 shipping = $2,400) is being defrayed, putting this unexpected purchase happily within our budget. More laptops = more happy kids!

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