| Tier Level | Requirements |
|---|
| 1 | - Single non-redundant distribution path serving the IT equipment
- Non-redundant capacity components
- Basic site infrastructure guaranteeing 99.671% availability
|
| 2 | - Fulfils all Tier 1 requirements
- Redundant site infrastructure capacity components guaranteeing 99.741% availability
|
| 3 | - Fulfils all Tier 1 & Tier 2 requirements
- Multiple independent distribution paths serving the IT equipment
- All IT equipment must be dual-powered and fully compatible with the topology of a site’s architecture
- Concurrently maintainable site infrastructure guaranteeing 99.982% availability
|
| 4 | - Fulfils all Tier 1, Tier 2 and Tier 3 requirements
- All cooling equipment is independently dual-powered, including chillers and Heating, Ventilating and Air Conditioning (HVAC) systems
- Fault tolerant site infrastructure with electrical power storage and distribution facilities guaranteeing 99.995% availability
|
