# Metrics

Charts of the router over the last hour, day, month or year, read every minute by default (see
[Settings](index.md#settings)).

## Charts

- CPU, memory, free disk space in bytes and in percent, and the load averages.
- Bytes per second of each interface, and the VPN clients.
- Per site-to-site connection: **Site-to-site up**, **Site-to-site traffic** and
  **Site-to-site packets**.

## Controls

- **Hour, Day, Month, Year:** the period shown.
- **Average, Maximum:** how each point sums up its time slot. Site-to-site up is always the
  percentage of the slot the connection was up: 5 minutes for an hour, 1 hour for a day, 1 day
  for a month and 1 month for a year.
- **Legend:** a click on a line's legend item hides or shows the line, for example the 1 and 5
  minute load averages to see the 15 minute one. The browser keeps the hidden lines.
- The charts fold, hide, move and change width as the [Router](router.md#layout) panels do, with
  a layout of their own.