Collaboration network testbed
While the OLPC Mesh Testbed is conveniently located in the same space used by OLPC for development and business activities, it suffers from an excess of unrelated wireless traffic. In order to allow repeatable testing of larger numbers of laptops, a larger testbed has been set up at another location in the Boston area, where the 802.11b spectrum is relatively unused.
At this location, we currently have a hundred laptops and a school server, along with a separate packet recording machine. We hope to grow to at least a hundred and fifty laptops over time.
While we will eventually provide remote automated control of large portions of the testing, we are currently performing tests manually.
Tests and Results
Simple Mesh
Startup
0317A
Laptop Build: 699
This was a staged startup of laptops. The packet trace was started five minutes before starting to turn the laptops on. The laptops were turned on in groups of five, with each group allowed to enter simple mesh mode before starting the next group.
The first ten laptops (X50 - X59) came up without a problem, with all laptops able to see the others.
One laptop (X69) in the third group of laptops (X65 - X69) came up without joining a simple mesh (Trac 5848). A reboot fixed the problem.
Another laptop (X73) in the fifth group of laptops (X70 - X74) came up with Trac 5848 and had to be rebooted before joining the simple mesh.
After rebooting two laptops, all 25 laptops (X50 - X74) could see the other 24 in their neighborhood view.
Packet Traces: Chan 1, Chan 11, Chan 6
Write Sharing
0317B
Laptop Build: 699
This test started with 25 laptops (X50 - X74) in a simple mesh on channel 1.
The Write activity was started on laptop X69 (169.254.1.204), and shared with the neighborhood.
The shared activity was seen on 24 of 25 laptops (X70 not showing). After further shared activity, it was eventually seen by all 25 laptops.
Ten laptops joined the shared activity, almost simultaneously. Three of the ten laptops launched write, but never showed the contents of the write document. The other seven correctly mirrored the shared document. The three laptops which failed to collaborate were X51 (169.254.5.153), X53 (169.254.2.7), and X54 (169.254.5.25).
More words were typed on X69, and were mirrored to the seven working laptops (no change in X51, X53, or X54).
Some words were typed on X59, and were correctly mirrored to the seven other collaborating laptops.
Packet Traces: Chan 1, Chan 11, Chan 6