For Webex Calling behind NAT or PAT, Cisco says to size the NAT pool, make sure the NAT device can translate overlapping source ports to unique ports, and avoid strict source-port preservation.

Checked 2026-09-25

Vendor
Cisco
Product
Webex Calling
Subsystem
network
Deployment
multi-tenant
Region
not restricted
Release range
current as of 2026-09-25
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP registration failures: source note sip-registration-failures-wxc-nat-port-overlap. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-wxc-nat-port-overlap

BibTeX

@misc{warmtransfer-claim-sip-registration-failures-wxc-nat-port-overlap,
  title  = {SIP registration failures: source note sip-registration-failures-wxc-nat-port-overlap},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-registration-failures-wxc-nat-port-overlap},
  note   = {Source note sip-registration-failures-wxc-nat-port-overlap, checked 2026-09-25}
}

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