SLA Basics
An uptime SLA is a contractual guarantee of availability. The difference between nines is larger than it appears.
Downtime Allowance
| SLA | Downtime / year |
|---|---|
| 99.9% | ~8.7 hours |
| 99.99% | ~52 minutes |
| 99.999% | ~5 minutes |
What to Look For
Check whether maintenance windows count against SLA, how credits are calculated, and whether network edge protection is included.