[tor-relays] Low observed bandwith

[Mario Costa]

Hi list,

I’m running a guard relay from my home connection on a Raspberry Pi 4. My internet connection is 1000/100 Mbps, and I thought I’d allocate half of the upload bandwidth for the relay. Then I set RelayBandwidthRate to 10 MB/s, because I thought that Tor would upload 5 MB/s and download 5 MB/s.

However, the maximum observed bandwidth was always about 6 MB/s. I’d like to know what could cause this low observed bandwidth. I don’t think it’s the Raspberry Pi, because CPU usage is always low and it has a Gigabit connection to the router.

The router itself easily reaches Gigabit speeds, so 10 MB/s should be a breeze. Could it be the number of connections? nyx indicates that the connections are always about 4000. If this is the case, how can I know if the connections bottleneck is the router or the Raspberry Pi?

Additionally, I’d like to ask for a rule of thumb for setting the RelayBandwithBurst. I set it to 20 MB/s because I’m ok with the relay using the whole upload bandwidth (about 10 MB/s, or 100 Mbps) for short periods of time, but as I already explained I’m never seeing such speeds.

For reference my relay’s fingerprint is F942EE73F1B8E39125F617FA85E80E4C9E540A2E.

-m