On 16/06/2020 12:16, Linus Lüssing wrote:
The new mesh_nolearn parameter allows to skip the PREQ/PREP exchange in
this scenario, leading to a reduced delay, reduced packet buffering and
simplifies HWMP in general.
And a third observation we've made with HWMP:
When running iperf with 16 parallel TCP streams and the default HWMP
parameters over two 4x4 802.11ac Wave 2 wifi cards transmitting about
800-1000 MBit/s in total, HWMP becomes quite unstable. We see frequent
PREQ/PREP retransmissions and also PERR messages, leading to spurious
break downs in the throughput.
When using just 8 TCP streams, so with a little less saturation and
stress of the channel, iperf staticstics are stable.
So maybe there would be some potential for optimizations, too, like
somehow prioritizing HWMP messages more, or maybe making the default
HWMP parameters a bit more conservative.
Or just disabling the HWMP PREP/PREQ/PERR exchange with this new
configuration option would at least help the ones that are using another
mesh routing protocol on top, who are maybe more familiar with the
parameters of their specific routing protocol than with the HWMP parameters.
Regards, Linus
