The rule against changing CallManager and TVS together follows from the ITL trust model. A phone that sees an unfamiliar ITL signer falls back to TVS, so if the TVS certificate changes in the same window the phone has no trusted path left.

inferred · Checked 2026-09-25

Vendor
Cisco
Product
Unified Communications Manager
Subsystem
itl
Deployment
on-premises
Region
not restricted
Release range
10.0(1) and later
Status
inferred
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). Unified CM certificate renewal: source note cucm-certificate-renewal-why-one-at-a-time. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-certificate-renewal-why-one-at-a-time

BibTeX

@misc{warmtransfer-claim-cucm-certificate-renewal-why-one-at-a-time,
  title  = {Unified CM certificate renewal: source note cucm-certificate-renewal-why-one-at-a-time},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/cucm-certificate-renewal-why-one-at-a-time},
  note   = {Source note cucm-certificate-renewal-why-one-at-a-time, checked 2026-09-25}
}

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