For SIP/TLS between Unified CM and Expressway-C, the Expressway-C server certificate or its CA root goes into the Unified CM trust store on all servers, and the CallManager certificate or its CA root goes into Expressway-C's trusted CA list.

Checked 2026-09-25

Vendor
Cisco
Product
Cisco Expressway with Unified CM
Subsystem
certificates
Deployment
on-premises
Region
not restricted
Release range
X8.1.1+ and Unified CM 10.0+
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). Expressway business-to-business calling: source note expressway-b2b-calling-cucm-cert-trust. WarmTransfer. https://warmtransfer.net/knowledge/claims/expressway-b2b-calling-cucm-cert-trust

BibTeX

@misc{warmtransfer-claim-expressway-b2b-calling-cucm-cert-trust,
  title  = {Expressway business-to-business calling: source note expressway-b2b-calling-cucm-cert-trust},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/expressway-b2b-calling-cucm-cert-trust},
  note   = {Source note expressway-b2b-calling-cucm-cert-trust, checked 2026-09-25}
}

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