Mesh Testing

This page describes the network testing that will be performed on Monday Feb 25th at 1cc.

Setup:

• Start with ten machines, keep adding ten at a time while it is useful to do so.

Measurements to make during each test (in addition to workload-specific measurements):

• Spectrum utilization -- as measured w/ spectrum analyzer and/or from wireshark
  • Wireshark may be able to break down bandwidth by packet type
• Remaining bandwidth -- attempt to download a large file on one machine during test, record time taken or bandwidth achieved.
• Total # of laptops seen on mesh view on all numbers (should be n^2).

Workloads -- tests to perform, along with their quantitative metrics:

1. Idle load.
2. Every machine coming out of suspend (or booting).
3. Every machine trying to register with school server -- Number of machines that failed the first attempt, failed second attempt, etc.
4. Ricardo's web spider at various rates of download (download 1k page/second, etc)
5. Read -- if one laptop shares a PDF, how many laptops fail to retrieve it?
6. Distance -- binary success/fail. Are there other metrics?
7. Write -- automate pressing N characters a second for small N, look at received rate/update time, increase number of participants per document.
8. olpc-update -- number of machines upgraded in 1 hour

Variables to investigate:

• Set mesh ttl to 1 for every packet
• Change bcast/mcast rate on every node
• Jim's Avahi config 30% fixes?
• Presence: Benchmark bandwidth use of Avahi vs. Cerebro vs. no presence?
• Collaboration: Benchmark switching from multicast to unicast?
• Suspend/resume: Off vs. on, wake-on-unicast vs. wake-on-multicast
• Block multicast in route table (are there other sources of multicast packets other than the above?)
• Would turning down the tx power (globally, since we can't do it per-packet) help with the dense mesh problems?
• Are there other mesh parameters to tweak? Path request timeout, for example.