Gigabit links through managed switch drops to 100M after a while

dweb-camp-2019 / meshnet

Mesh @ DWeb Camp 2019 📡

https://dweb-camp-2019.github.io/meshnet/

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Gigabit links through managed switch drops to 100M after a while #27

Closed benhylau closed 4 years ago

benhylau commented 5 years ago

These are wireless wire links normally talking at 800 Mbps, passing thru Netgear gigabit managed switch for VLAN tagging, and into espressobin. Some of these links fall to 94 Mbps (100M) speeds all of a sudden and stay there. Tested with different cat5e cables. Suspect this is related to the Netgear switch. Rebooting it or entire node doesn't help. Same links have recorded 800+ Mbps.

Suspect: Netgear managed switch

Switch setting
Heat dissipation related
Number of active ports
Firmware

benhylau commented 5 years ago

Today we found this also happens without the managed switch in between. Wireless Wires radio test is 800+ Mbps but espressobin iperf3 94 Mbps. And WW logs show downgrading link to 100M

benhylau commented 5 years ago

There is a good chance this is related to heating of the espressobin switch chip. This is only observed in the outdoor node-38 with its two Wireless Wire links (one to indoor node-23 and another to outdoor solar node. The indoor node-23 is similarly configured and has another Wireless Wire link to node-86 and that maintains gigabit speeds.

Next steps:

Set up and try to reproduce
Probe temperatures
Add active cooling (got some powerful fans from Sam @ IA which can be powered off of SATA HDD power on Espressobin, 12V or 5V both work)

benhylau commented 4 years ago

Bad ethernet cable :(