[Babel-users] Restarting MeshPoint – seeking advice on routing for crisis/disaster scenarios

[Juliusz Chroboczek]

> For networks larger than ~250 nodes, single-host simulation becomes
> unreliable regardless of available RAM.

I can probably ask for access to a 64-core server, in case that helps.
Please let me know.

> ---------------
> Our initial tests with babeld show:
>   Grid 100 nodes:       100% connectivity, ~14s convergence
>   Chain 50 nodes:       100% connectivity, ~5s convergence
>   Small-world 100 nodes: 100% connectivity, ~12s convergence

By default, Babel uses a hello interval of 4s.  Your results are between
1 and 3.5 hello inervals, and I suspect that you're measuring the
performance of the link quality estimator: the link quality estimator
needs 3 hello intervals to converge, and the protocol converges almost
immediately afterwards.

In order to test this hypothesis, please try reducing Babel's hello
interval (to 1s, then to 0.5s, then to 0.1s, then to 0.05 s).  As long as
the convergence time is on the order of 3 hello intervals, you're
measuring the performance of the link quality estimator.  Once the
convergence time is significantly higher than 3 hello intervals, you're
measuring the performance of the routing protocol itself.

-- Juliusz