Zoom Phone Local Survivability

Zoom Phone Local Survivability: Maintaining telephony during a service-impacting event

Zoom Phone Local Survivability (ZPLS) is a survivability-based service module that provides Zoom Phone users with failover functionality, connectivity, and survivability in the event of an internet or service disruption.

During a survivability event when Zoom endpoints can’t reach the Zoom Phone cloud, supported user devices automatically register with the ZPLS module as their third-priority registrar—after the primary and secondary SIP zones. This registration enables basic telephony services, such as internal calling and survivability distribution groups, until full service is restored.

When properly configured, ZPLS modules across different sites can support cross-site calling during a survivability event, as long as devices are discoverable on the local network and call forwarding is enabled.

Organizations can further expand this capability by connecting the ZPLS module to a Session Border Controller (SBC) and route calls over the public switched telephone network (PSTN) via Bring Your Own Carrier (BYOC). This hybrid approach combines the simplicity of cloud-managed telephony with the resilience of on-premises infrastructure—helping ensure business continuity even when the unexpected happens.

However, survivability may still be impacted if the local network itself fails—particularly in single-site deployments where buildings depend on a shared campus network.

The following images show sample deployment configurations for Zoom Phone Local Survivability across a range of site and network topologies.

Refer to your Zoom account team or Zoom’s support center for more information on Zoom Phone Local Survivability.