Can anybody explain the Advertised bandwidth, MaxAdvertisedBandwidth, Measured bandwidth, Bandwidth burst, RelayBandwidth rate?

Question

I am confused about a few terms: AdvertisedBandwidth, MaxAdvertisedBandwidth, MeasuredBandwidth, RelayBandwidthBurst, RelayBandwidthRate, BandwidthBurst, and BandwidthRate. Can anyone please explain these terms?

Answer 1

I'll give it a try:

• BandwidthBurst: The maximum bandwidth of short spikes in network traffic. While Tor tries to use BandwidthRate on average, it may use this value for short bursts. It was advised that this value should be four times the BandwidthRate.
• BandwidthRate: The average bandwidth Tor should use.
• RelayBandwidthBurst and RelayBandwidthRate: Both values deal with relayed traffic and have the same meaning as the ones above.
• AdvertisedBandwidth: I'm not aware of such a name. If you have a look at Atlas, you'll find a value there for advertised bandwidth (see politkovskaja as an example). This is the value which the directory authority measures.
• MaxAdvertisedBandwidth: This is the maximum bandwidth your server claims to have. If you run a relay and don't set any limits, Tor will try to use all available bandwidth. Sometimes the bandwidth is so high that the CPU can't handle it anymore. You'll see warnings in the Tor logfile. In the case it is wise to set MaxAdvertisedBandwidth, because it tells the outside world that your bandwidth is smaller and so attracts less clients. Someone suggested that this should be 30% more than BandwidthRate.
• MeasuredBandwidth: There is no configuration option with this name. However directory authorities measuring the traffic and might use such a name.

Within the comments you mentioned a bandwidth from the microdesc-consensus. An entry looks like:

r TorNinurtaName AA8YrCza5McQugiY3J4h5y4BF9g 2014-06-23 08:06:30 151.236.6.198 9001 9030
m sB1HNyL+qngrnX8/DhRPZNfX/SbL+jvs3CE7k3v0kMg
s Fast Guard HSDir Named Running Stable V2Dir Valid
v Tor 0.2.4.22
w Bandwidth=2470

The last line is an estimated bandwidth. You can find some details in the specification.