Secure MRA registrations fail if the Expressway-C server certificate's Subject Alternative Names do not include the phone security profile names in use, and from X12.6 those profile names must be FQDNs in both Unified CM and the certificate.

Checked 2026-09-24

these names — in both Unified CM and in the Cisco Expressway's certificate — must be in FQDN format
Vendor
Cisco
Product
Expressway
Subsystem
MRA certificates
Deployment
on-premises
Region
not restricted
Release range
X12.6 and later; documented in X15.2
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). Troubleshooting Cisco IP phone registration: source note cisco-phone-registration-troubleshooting-mra-san. WarmTransfer. https://warmtransfer.net/knowledge/claims/cisco-phone-registration-troubleshooting-mra-san

BibTeX

@misc{warmtransfer-claim-cisco-phone-registration-troubleshooting-mra-san,
  title  = {Troubleshooting Cisco IP phone registration: source note cisco-phone-registration-troubleshooting-mra-san},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/cisco-phone-registration-troubleshooting-mra-san},
  note   = {Source note cisco-phone-registration-troubleshooting-mra-san, checked 2026-09-24}
}

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