PSTN Integration Considerations | Zoom Technical Library

Publisher

Zoom Communications

URL

https://library.zoom.com/zoom-workplace/zoom-phone/zoom-phone-local-survivability-field-guide/before-you-begin/pstn-integration-considerations

Published

unknown

Updated

unknown

Accessed

2026-09-24

HTTP status

200

License

Zoom proprietary; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

• Because ZPLS sends survivability PSTN calls through the customer SBC and requires a BYOC ELIN, a site served only by Zoom Phone Native numbers is unlikely to have PSTN egress during a survivability event without adding BYOC-P. inferred in context
• During survivability, emergency calls present a single site-level ELIN, which must be a BYOC number terminating on the failover SBC's PSTN trunk, and ZPLS routes emergency callbacks to the original caller for up to 2 hours. in context
• During a survivability event, outbound calls from the ZPLS module go to the SBC and its PSTN SIP trunk and present the user's BYOC number as calling party. in context
• Any SBC certified for Zoom Phone BYOC can be used with the Zoom Phone Local Survivability module, and existing BYOC customers do not need a separate SBC for survivability. in context
• With ZPLS, the customer SBC must route inbound PSTN calls to the primary and secondary Zoom data center SIP zones first, with the ZPLS module as the tertiary choice used only during survivability events. in context

Cite this source record

APA

WarmTransfer. (2026, September 24). PSTN Integration Considerations | Zoom Technical Library. WarmTransfer. https://warmtransfer.net/knowledge/sources/zoom-library-zpls-pstn-integration

BibTeX

@misc{warmtransfer-zoom-library-zpls-pstn-integration,
  title  = {PSTN Integration Considerations | Zoom Technical Library},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/zoom-library-zpls-pstn-integration},
  note   = {Zoom Communications, accessed 2026-09-24}
}