# rtt\_thresholds

Hot Reloadable

Applies only when the `s2_auto` mode is used and defines the round-trip time (RTT) thresholds for compression level changes.

By default, no compression is used unless the RTT hits the first threshold (e.g. 10ms), then `s2_fast`. The next threshold would switch to `s2_better`, and then finally `s2_best` is the last threshold is reached.

Note, the compression level is dynamic so if the RTT decreases, the compression level will decrease accordingly.

## Types

| Type           | Description                                                    | Choices |
| -------------- | -------------------------------------------------------------- | ------- |
| `[ duration ]` | Duration as a string with units such as 100ms, 10s, 5m, or 2h. | -       |