jitter
A random amount added to or taken from a retry wait so many devices don't retry at the same instant.
Jitter randomizes each backoff wait (full jitter picks uniformly from zero up to the wait; equal jitter keeps half and randomizes the other half), which spreads the retries of a whole fleet after a shared outage.
Examples
When a server restart drops 10,000 devices, jitter spreads their fourth retry (8 s) over a window like 4 to 8 s instead of one instant.
Two devices with the same base, factor and cap still retry at slightly different moments because each adds its own random amount.