An Availability Zone is a customer-defined set of Proximity Cloud racks which all share external connectivity and management services.

The simplest (and default) Proximity Cloud offering includes a single Availability Zone containing a single rack.

A customer who wishes to install multiple Proximity Clouds at the same datacentre has the choice - they can setup the Proximity Clouds within a single Availability Zone (if there is good enough connectivity between the racks - ideally they would be in contiguous space), or for extra resilience the customer can setup each Proximity Cloud rack in its own Availability Zone.

Certain customers can choose to offer compute resources within their availability zone to multiple clients. This multitenant type deployment is described in more detail throughout this document, and in particular in Viewing tenant portals and Assigning and Releasing Compute from Tenant Portals .

Note: Direct layer 2 network communication is not possible between compute in different Availability Zones.