TCP Retransmit Ratio Is Better Than Counting Retransmits Alone

A few retransmissions during heavy traffic may be normal, while the same count during low traffic can represent a serious quality problem. On hserver the first signal I use for this question is TCP retransmits divided by transmitted TCP segments. A ratio normalizes retransmission against traffic volume and makes comparison across quiet and busy periods more meaningful.

The important part is interpretation rather than collecting another graph. normalized error-rate monitoring. That gives the metric a specific operational job instead of making it another number on a dashboard.

The practical control is straightforward: Track both absolute rate and ratio, then correlate spikes with packet drops, Wi-Fi signal, tunnel logs and public latency. This also gives me a repeatable check after deployments, exporter changes, or capacity tuning.

Repository evidence for this monitoring behavior is commit b65d5d4. I keep that reference with the note because a monitoring conclusion is stronger when the configuration and runtime decision that produced it can be inspected later.