Collab Network School Wifi Tests

In these collaboration and networking tests, the laptops are connected to the School server through normal 802.11b/g access points. In general, the laptops are registered with the school server and using the school's presence service.

Other networking modes tested are simple mesh and school mesh.

Presence

Test 0323J

Laptop Build: 699 + telepathy-salut-0.2.3-1.olpc2.i386.rpm

School Server Build: 160 + 22.p6 Libertas firmware

School Server Channels: Linksys WiFi AP on channel 1

This test was a simultaneous startup of 37 laptops. It was determined that the AP only supported up to thirty simultaneous connections. Other laptops were unable to connect to the school server.

Thirty-seven laptops (X50 - X59, X62 - X79, X90 - X98) were turned on sequentially, with around one sec between each one. All laptops had previously been registered with the school server. All laptops started a simple mesh. Manually, they each were instructed to use the linksys access point by clicking on its circle (icon) in the neighborhood view.

The first thirty laptops connected to the school server, and displayed presence information about all the other connected laptops. The remaining seven laptops (X54, X59, X64, X75, X90, X91, and X98) were unable to associate with the AP.

The logging was conducted with three Active Antennas, separated by one meter, all on channel 1.

Packet Traces: Due to operator error, we do not have packet traces for this test (I forgot to change mode of sniffing interfaces, and associate them with Access Point. Even though they were monitoring the correct channel they did not capture any traffic). Chan 1 (a), Chan 1 (b), Chan 1 (c)

Server logs: /var/log/messages, laptop list

Test 0323K

Laptop Build: 699 + telepathy-salut-0.2.3-1.olpc2.i386.rpm

School Server Build: 160 + 22.p6 Libertas firmware

School Server Channels: Linksys WiFi AP on channel 1

This test was a simultaneous startup of 30 laptops, previously connected to a school server through an AP. None of the laptops tried to connect with the previous AP. 29 of them formed a simple mesh, with one deciding not to talk to anybody.

Thirty laptops (X50 - X53, X55 - X58, X62 - X63, X65 - X74, X76 - X79, X92 - X97) were turned on sequentially, with around one sec between each one. All laptops had previously been registered with the school server, and had used this AP the last time they were powered on.

All laptops started a simple mesh, except for X55, which didn't show any network connection (Trac 5848).

I was surprised. I thought the default behavior was to associate with the previous network, if found!

The logging was conducted with three Active Antennas, separated by one meter, all on channel 1.

Packet Traces: Due to operator error, we do not have packet traces for this test (forgot to change mode of sniffing interfaces, and associate them with Access Point. Even though they were monitoring the correct channel they did not capture any traffic. Chan 1 (a), Chan 1 (b), Chan 1 (c)

Laptop X55 logs: All, dmesg, /var/log/messages, Telepathy/Sugar

Server logs: /var/log/messages, laptop list

Write

Test 0330A

Laptop Build: 703 + Write 55

Channels: Airport AP on channel 10

This test was not performed at the Collaboration Networking Testbed, but in a similarly quiet RF environment.

This test was a test of Write collaboration between two laptops, connected through a WiFi access point. No school server was accessible through the access point (although one was running on channel 1).

Two laptops were turned on, and the "Watlington" network was selected from their neighborhood view. Each laptop saw the other in their neighborhood view.

Write was started on Evan (aka 172.24.0.34 aka 00:17:c4:0c:e2:1f), and shared with the neighborhood. The shared activity was immediately visible in the neighborhood view of Adrian (aka 172.24.0.38 aka 00:17:c4:0c:e2:8b). Clicking on the shared activity launched it, and showed what had been written on Evan so far. Both laptops were able to type, and have it appear on the other, although if one laptop typed really fast, there was a perceptible latency (3-4 sec) before the characters appeared on the other laptop.

The logging was conducted with one Active Antenna.

Packet Traces: Chan 10

Measure

Test 0330B

Laptop Build: 703 + Measure 15

Channels: Airport AP on channel 10

This test was not performed at the Collaboration Networking Testbed, but in a similarly quiet RF environment.

This test was a test of Measure collaboration between two laptops, connected through a WiFi access point. No school server was accessible through the access point (although one was running on channel 1).

Two laptops were turned on, and the "Watlington" network was selected from their neighborhood view. Each laptop saw the other in their neighborhood view.

Measure was started on Evan (aka 172.24.0.34 aka 00:17:c4:0c:e2:1f), and shared with the neighborhood. The shared activity was immediately visible in the neighborhood view of Adrian (aka 172.24.0.38 aka 00:17:c4:0c:e2:8b). Clicking on the shared activity launched it. After clicking on Begin Measurement on both laptops, the laptops correctly calculated the distance between them for a minute before being stopped.

The logging was conducted with one Active Antenna.

Packet Traces: Chan 10