Source note · Zoom Phone routing and PSTN connectivity
Zoom fails over to an alternate SBC when the primary is down on OPTIONS keepalive or answers an INVITE with 403, 408, 480, 488, 500, 502, 503, 504 or 606.
Checked 2026-09-24
SBC generates a 403, 408, 480, 488, 500, 502, 503, 504 or 606 response to INVITE from Zoom.
- Vendor
- Zoom
- Product
- Zoom Phone; Zoom Contact Center
- Subsystem
- byoc-p-resilience
- Deployment
- hybrid
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- BYOC-P or BYOP-P call processing — Zoom Communications · tier 2 current vendor documentation · Failover routing
Cite this note
APA
WarmTransfer. (2026, September 24). Zoom Phone routing and PSTN connectivity: source note zoom-phone-routing-failover-response-codes. WarmTransfer. https://warmtransfer.net/knowledge/claims/zoom-phone-routing-failover-response-codes
BibTeX
@misc{warmtransfer-claim-zoom-phone-routing-failover-response-codes,
title = {Zoom Phone routing and PSTN connectivity: source note zoom-phone-routing-failover-response-codes},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/zoom-phone-routing-failover-response-codes},
note = {Source note zoom-phone-routing-failover-response-codes, checked 2026-09-24}
}