Collab Network School Wifi Tests

In these collaboration and networking tests, the laptops are connected to a 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, simple wifi and school mesh.

Presence

Test 0410A

Laptop Build: 703

School Server Build: 160

School Server Channels: Zoom Model 4400 "AP+2" on channel 1

This test was a fast startup of 76 laptops. After four minutes, 13 of the 76 had either lost their network altogether (5848) or failed to associate (Trac 6811). Of the 63 laptops that connected to the school AP, ten failed to contact the school presence server (Trac 6881), and another seven had other presence problems (Trac 6882, Trac 6883).

Seventy six laptops (X00 - X39, X50 - X59, X62 - X79, X90 - X98) were turned on over a period of one minute. All of the laptops had previously been associated with the school WiFi AP, and previously registered with the school server (in Test 0408B and Test 0408C).

Eleven of the laptops (X02, X05, X27, X31, X36, X51, X52, X54, X59, X90, and X97) did not associate with the school AP, and formed a simple mesh on channel 1 instead (Trac 6811).

Two of the laptops (X73 and X94) did not even start a simple mesh (Trac 5848).

It should be noted that the laptops exhibiting problems are generally those which were started later.

On the remaining 60 laptops, we looked to see if a gabble connection was formed with the presence service on the school server.

Ten of the laptops (X00, X04, X13, X20, X53, X58, X63, X72, X79, and X95) were running salut (the distributed presence service that is started up if the laptop cannot connect with the school presence service) Trac 6881

Five of the laptops (X07, X11, X50, X62, and X75) were running salut AND gabble. They showed presence information from salut in their neighborhood view (Trac 6882).

Two of the laptops (X32, X68) were running gabble, but were not showing any other laptops in their neighborhood view (Trac 6883).

The school presence service (ejabberd) indicated that 55 laptops were online. We frequently see this service indicating that machines which are no longer online are still connected (for up to an hour afterwards).

Restarting Sugar (CTL ALT ERASE) corrected the problems, and the laptops correctly connected to the school presence service using Gabble.

The packet logging was conducted with three Active Antennas, separated by one meter, all on channel 1. Unfortunately, some of the test laptops (X00 - X19, X30 - X39) did not have debug logging enabled for this test.

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c)

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

No Association

Laptop X54 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X05 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs)

No Simple Mesh

Laptop X94 logs: All, info, /var/log/messages, Telepathy/Sugar

Running Salut

Laptop X63 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X72 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X00 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs)

Running Salut and Gabble

Laptop X50 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X11 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs)

Running Gabble, but no neighbors shown

Laptop X68 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X32 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs)

Test 0410B

Laptop Build: 703

School Server Build: 160

School Server Channels: Zoom Model 4400 "AP+2" on channel 1

This test was a fast startup of 50 laptops. After four minutes, all had associated with the school WiFi network. One of the laptops failed to contact the school presence server (Trac 6881), and another seven had other presence problems.

Fifty laptops (X05 - X08, X10 - X20, X25 - X29, X32 - X34, X50 - X59, X62 - X79) were turned on over a period of one minute. All of the laptops had previously been associated with the school WiFi AP, and previously registered with the school server (in Test 0408B and Test 0408C).

All of the laptops sucessfully associated with the school WiFi AP.

We then checked to see if a gabble connection was formed with the presence service on the school server.

One of the laptops (X65) was running salut (Trac 6881).

At least seven of the laptops (X17, X25, X28, X66, X67, X76, X77) were running gabble, but not showing all of the other laptops in their neighborhood view (Trac 6884). For example, X17 was only showing 27 laptops, X25 was showing 25, and X28 was only showing 34. The rest were showing between forty and fifty laptops.

One of the laptops (X59) was running gabble, but was not showing up on other laptop's neighborhood views (Trac 6888). It showed up on 2 of the 30 laptops checked.

The school presence service (ejabberd) indicated that 66 laptops were online. This was forty minutes after laptops from the previous test were powered off.

Restarting Sugar (CTL ALT ERASE) corrected the problems, and the laptops correctly connected to the school presence service using Gabble.

The packet logging was conducted with three Active Antennas, separated by one meter, all on channel 1. Unfortunately, some of the test laptops (X00 - X19, X30 - X39) did not have debug logging enabled for this test.

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c)

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

Laptop X65 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X25 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X28 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X76 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X17 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs, only errors)

Laptop X59 logs: All, info, /var/log/messages, Telepathy/Sugar

Test 0410C

Laptop Build: 703

School Server Build: 160

School Server Channels: Zoom Model 4400 "AP+2" on channel 1

This test was a fast startup of 50 laptops. After five minutes, 2 of the 50 had failed to associate (Trac 6811). Of the 48 laptops that connected to the school AP, four failed to contact the school presence server (Trac 6881), two had other presence problems (Trac 6882, Trac 6883), and many others weren't showing all laptops (Trac 6884).

Fifty laptops (X05 - X08, X10 - X20, X25 - X29, X32 - X34, X50 - X59, X62 - X79) were turned on over a period of one minute. All of the laptops had previously been associated with the school WiFi AP, and previously registered with the school server (in Test 0408B and Test 0408C).

Two of the laptops (X10 and X63) did not associate with the school AP, and formed a simple mesh on channel 1 instead (Trac 6811).

On the remaining 48 laptops, we looked to see if a gabble connection was formed with the presence service on the school server.

Four of the laptops (X29, X33, X69, and X77) were running salut (Trac 6881).

One of the laptops (X62) was running salut AND gabble. It showed presence information from salut in its neighborhood view (Trac 6882).

One of the laptops (X67) was running gabble, but was not showing any other laptops in its neighborhood view (Trac 6883).

A number of laptops were showing less that the correct number of XOs (Trac 6884). For example, this table shows how many of each group of XOs three laptops could see:

Laptop	X0i	X1i	X2i	X3i	X5i	X6i	X7i	Total Seen
Ideal	4	9	5	2	10	6	9	45
X26	4	7	3	2	10	5	5	36
X27	4	9	4	2	10	6	9	44
X28	2	3	2	1	7	4	4	23

The school presence service (ejabberd) was restarted (the entire server was rebooted) to clear its idea of which laptops were present before this test was started. It indicated that 45 laptops were online at this point.

The packet logging was conducted with three Active Antennas, separated by one meter, all on channel 1. Unfortunately, some of the test laptops (X00 - X19, X30 - X39) did not have debug logging enabled for this test.

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c)

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

Laptop X63 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X10 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs)

Laptop X26 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X27 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X28 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X62 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X67 logs: All, info, /var/log/messages, Telepathy/Sugar

Test 0410D

Laptop Build: 703

School Server Build: 160

School Server Channels: Zoom Model 4400 "AP+2" on channel 1

This test was a fast startup of 49 laptops, while a 50th laptop was continuously downloading a large file. After five minutes, 5 of the 49 had failed to associate (Trac 6811, Trac 5848). Of the 44 laptops that connected to the school AP, four failed to contact the school presence server (Trac 6881) and another two had other presence problems (Trac 6882).

A laptop (X59 aka 00:17:c4:11:01:f0) was started downloading files from the HTTP server on the school server. It downloaded thirty 1 MB files, followed by ten 10 MB files, then repeated the process indefinitely.

Forty nine laptops (X05 - X08, X10 - X20, X25 - X29, X32 - X34, X50 - X58, X62 - X79) were then turned on over a period of one minute. All of the laptops had previously been associated with the school WiFi AP, and previously registered with the school server (in Test 0408B and Test 0408C).

Four of the laptops (X12, X17, X20 and X33) did not associate with the school AP, and formed a simple mesh on channel 1 instead (Trac 6811).

One of the laptops (X07) did not even start a simple mesh (Trac 5848).

On the remaining 44 laptops, we looked to see if a gabble connection was formed with the presence service on the school server.

Four of the laptops (X11, X57, X58, and X29) were running salut (Trac 6881).

Two of the laptops (X62 and X66) were running salut AND gabble. They showed presence information from salut in their neighborhood view (Trac 6882).

The packet logging was conducted with three Active Antennas, separated by one meter, all on channel 1. Unfortunately, some of the test laptops (X00 - X19, X30 - X39) did not have debug logging enabled for this test.

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c) (caution, 780 MB each!)

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

Laptop X07 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs)

Laptop X12 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs)

Test 0408B

Laptop Build: 703

School Server Build: 160

School Server Channels: Zoom Model 4400 "AP+2" on channel 1

This test was a staged startup of 38 laptops. Ten of the laptops had previously been associated with the school WiFi AP, the rest needed to be manually connected. Around 28 of the laptops had been previously registered with the school server (in Test 0331G). In the end, all 38 laptops were able to associate with the access point and register with the server.

First, twenty laptops (X50 - X59, X62 - X71) were turned on simultaneously. All ten machines previously using that access point associated with it again. All of the new machines were manually associated with the school AP, then registered. All registered successfully on the first try.

Once a laptop was registered for the first time, Sugar was restarted.

Eight more laptops (X72 - X79) were turned on, followed by 10 more (X20 - X29). All were manually associated with the school AP and registered. There were problems registering some of the laptops (e.g. X25). We discovered that if an attempt to register the laptop was made on a network without a school server, Sugar would silently refuse to perform another registration attempt until restarted (Trac 6857). Once we realized what the problem was, we were able to register all laptops on the first try.

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

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c)

Laptop X25 logs: All, info, /var/log/messages, Telepathy/Sugar

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

Test 0408F

Laptop Build: 703

School Server Build: 160

School Server Channels: Zoom Model 4400 "AP+2" on channel 1

This test was a fast startup of 77 laptops. All of the laptops had previously been associated with the school WiFi AP, and previously registered with the school server (in Test 0408B and Test 0408C). In the end, all but six of the laptops were able to associate with the access point. Due to timing of the test, we are unsure how many successfully joined Gable.

Seventy seven laptops (X00 - X39, X50 - X59, X62 - X79, X90 - X98) were turned on sequentially, roughly four laptops per second.

One of the laptops (X31) did not even start a simple mesh (Trac 5848).

Five other laptops (X00 neé X100, X04, X15, X18, and X23) did not re-associate with the school AP, and created a simple mesh instead (Trac 6811).

As this test was conducted immediately after Test 0408C, the school presence service was maintaining state and made it impossible to determine which laptops were properly connected using Gabble.

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

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c)

Laptop X31 logs: All, info, /var/log/messages, (we screwed up and didn't enable the sugar logs on this laptop.)

Laptop X23 logs: All, info, /var/log/messages, Telepathy/Sugar

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

Test 0331G

Laptop Build: 703

School Server Build: 160 + 22.p6 Libertas firmware

School Server Channels: Linksys WiFi AP on channel 1

This test was a simultaneous startup of 28 unregistered laptop. It was sheer chaos! Laptops had problems associating with the access point and registering with the school server. Many of the laptops took multiple tries to associate with the "linksys" network, and multiple tries to register with the school server (Trac 6857).

All laptops (X50 - X59, X62 - X79) were turned on simultaneously. Once booted, it frequently took several attempts to overrule the pre-programmed school server search algorithm by clicking on the "linksys" network in the neighborhood view. Some laptops (X73, X74, X54) proved particularly difficult, and were turned off (once logs were copied).

Once the laptops were connected with the "linksys" network, they were registered. Unlike previous experiments with registration, it frequently took a number of tries to register a laptop (probably due to Trac 6857).

Once a laptop was registered, Sugar was restarted.

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

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c)

Laptop X54 logs: All, /var/log/messages, Telepathy/Sugar

Laptop X74 logs: All, /var/log/messages, Telepathy/Sugar

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

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! Logged as Trac ticket 6811.

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 0410F

Laptop Build: 703 + Write 55 + Chat 35

School Server Build: 160

School Server Channels: Zoom Model 4400 "AP+2" on channel 1

This test was tried sharing Write using 40 laptops, while also conducting a Chat between said laptops (and nine more laptops), while a 50th laptop was continuously downloading a large file. All laptops were able to join the shared Write activity, contribute, and see the contributions on everyone's screen. The latency seen between the screen being typed on and other screens could be incredible (minutes, with seconds between characters), but eventually the edits did correctly resolve!

A laptop (X69 aka 00:17:C4:0D:00:01) was downloading files from the HTTP server on the school server. It downloaded thirty 1 MB files, followed by ten 10 MB files, then repeated the process indefinitely.

Forty nine laptops (X05 - X08, X10 - X20, X25 - X29, X32 - X34, X50 - X58, X62 - X79) had previously been associated with the school LAN, connected to the school presence service, and were running a shared Chat activity at the start of this test, from a previous test (Test 0410E).

Write was started on laptop X69 (aka 00:17:C4:0D:3A:29), and shared with the neighborhood. It was seen on all other laptops.

Forty laptops joined the shared activity, starting in order from X62 on up, then moving down. All laptops were able to join the Write, and saw the shared document. Text typed on any laptop was seen on all other laptops, although sometimes a delay of over a minute was incurred before it appeared on other laptops.

Unfortunately, the packet traces were lost, due to misbehavior of the tracing machine.

Test 0331H

Laptop Build: 703 + Write 55

School Server Build: 160 + 22.p6 Libertas firmware

School Server Channels: Linksys WiFi AP on channel 1

This test started with 24 laptops which supposedly were connected to a School server through a WiFi access point. After noticing differences in laptops' neighborhood views, Sugar was restarted on all laptops. Finally, a Write activity was shared, but nobody saw it.

This test started after a previous experiment in registration. All the laptops had been registered, but they weren't properly communicating with the school presence service. After noticing a number of laptops with 10, 12, 14, etc..., neighbors shown, I checked the ejabberd online users page (http://172.18.0.1:5280/admin) and only saw around ten laptops. I restarted Sugar again on all the laptops, and finally saw 24 laptops online with ejabberd.

X53 was a laptop which still showed only two laptops, after restarting Sugar.

The Write activity was started on laptop X69. The activity was shared with the neighborhood. No other laptop saw the shared activity.

The logging was conducted with three Active Antennas, separated by one meter, all on channel 1. The logs are divided up into two parts, part 1 and part 2.

Packet Traces: Chan 1(a) pt1, Chan 1(a) pt2, Chan 1(b) pt1, Chan 1(b) pt2, Chan 1(c) pt1, Chan 1(c) pt2

Laptop X53 logs: All, /var/log/messages, Telepathy/Sugar

Laptop X69 logs: All, /var/log/messages, Telepathy/Sugar

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

Chat

Test 0410E

Laptop Build: 703 + Chat 35

School Server Build: 160

School Server Channels: Zoom Model 4400 "AP+2" on channel 1

This test was tried chat using 49 laptops, while a 50th laptop was continuously downloading a large file. Two the laptops had trouble seeing the chat session because they had switched back to salut (Trac 6886). All laptops were able to join the Chat, contribute, and see the contributions on everyone's screen.

A laptop (X59 aka 00:17:c4:11:01:f0) was started downloading files from the HTTP server on the school server. It downloaded thirty 1 MB files, followed by ten 10 MB files, then repeated the process indefinitely.

Forty nine laptops (X05 - X08, X10 - X20, X25 - X29, X32 - X34, X50 - X58, X62 - X79) had previously been associated with the school LAN and connected to the school presence service in a previous test (Test 0410D). Any laptops exhibiting problems in that test had that problem corrected before starting this test.

Chat was started on laptop X79 (aka 00:17:C4:0D:3A:29), and shared with the neighborhood.

It was seen on all other laptops but two. Laptops (X05 and X08) appeared to have reverted to running salut, and were unable to see the chat (Trac 6886). Sugar was restarted (CTL ALT ERASE) to fix the problem.

All laptops were able to join the chat. Text typed on any laptop was immediately seen on all other laptops.

The packet logging was conducted with three Active Antennas, separated by one meter, all on channel 1. Unfortunately, some of the test laptops (X00 - X19, X30 - X39) did not have debug logging enabled for this test.

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c) (caution, 650 MB each!)

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

Laptop X05 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs)

Laptop X08 logs: All, info, /var/log/messages, Telepathy/Sugar (no debug logs)

Test 0408C

Laptop Build: 703 + Chat 35

School Server Build: 160

School Server Channels: Zoom Model 4400 "AP+2" on channel 1

This test was a test of Chat, starting with 38 laptops, while adding another 40 laptops to the network. By the end of the test, 78 laptops were associated with the mesh, and 75 laptops were successfully chatting.

Thirty-eight laptops were started and associated with the school AP in a previous test. Chat was started on X62, and shared with the neighborhood. All associated laptops immediately saw the shared activity.

An additional twenty laptops were turned on and associated with the school AP, registered with the server, and Sugar restarted. These laptops then joined the Chat.

An additional seventeen laptops were turned on and associated with the school AP, registered with the server, and Sugar restarted. These laptops then joined the Chat.

Some of the laptops (e.g. X97, X13) had problems registering with the school server, but in case it was determined to be the problem now known as Trac 6857.

The logging was conducted with three Active Antennas, separated by one meter, all on channel 1. This test took a while to performs, so the packet trace was stopped and restarted.

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c) (later) Chan 1(a), Chan 1(b), Chan 1(c) (even later) Chan 1(a), Chan 1(b), Chan 1(c)

Packet Traces: Chan 1(a), Chan 1(b), Chan 1(c)

Laptop X97 logs: All, info, /var/log/messages, Telepathy/Sugar

Laptop X13 logs: All, info, /var/log/messages, Telepathy/Sugar (we screwed up and didn't enable debug logging, but there are errors logged !)

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