This is a little write-up on the quality of data connections involving nodes, and some thoughts on that. So, as of today, the quality of nodes is determined by their bandwidth, uptime, and not being malicious. There are two major missing factors from this, and I wanted to bounce some ideas around: Latency and Packet Loss. These are fairly simple tests that can be performed on nodes, albeit, it would increase the resource load on the bwauths. However, nodes with high latency or packet loss should be identified, and nodes should be measured with these two important factors.

High latency will increase the delay of the circuit, but will not appear in the consesus at all. A node can have enormous latency and hamper that circuit without anyone knowing. The same could be said for a node that drops a lot of packets, or drops a lot of packets at a certain time of day (peak usage).

Mostly, latency and packet loss in nodes will negatively impact Tor's usability, but not it's security. However, bwauth testing of node latency can create a foundation of data in which we can disrupt Timing Attacks on the network. Also, as of the moment, node operators should just briefly look into these numbers for their nodes. Ensuring their nodes don't have a high latency or packet loss problem when connecting to, for example, google.com.