On a TLS trunk, an untrusted far-end certificate or an X.509 Subject Name mismatch stops the TLS session before OPTIONS can be exchanged, so OPTIONS ping cannot succeed and the trunk stays out of service.
inferred · Checked 2026-10-02
- Vendor
- Cisco
- Product
- Unified Communications Manager
- Subsystem
- SIP TLS
- Deployment
- on-premises
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Status
- inferred
- Checked
- 2026-10-02
Sources
- Security Guide for Cisco Unified Communications Manager, Release 15 and SUs - Trunk and Gateway SIP Security — Cisco Systems · tier 2 current vendor documentation · SIP Trunk Security Profile Settings > X.509 Subject Name (combined with 213718 Local=2 description)
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting Unified CM SIP trunks that show No Service: source note cucm-sip-trunk-no-service-troubleshooting-tls-fail-inference. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-sip-trunk-no-service-troubleshooting-tls-fail-inference
BibTeX
@misc{warmtransfer-claim-cucm-sip-trunk-no-service-troubleshooting-tls-fail-inference,
title = {Troubleshooting Unified CM SIP trunks that show No Service: source note cucm-sip-trunk-no-service-troubleshooting-tls-fail-inference},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-sip-trunk-no-service-troubleshooting-tls-fail-inference},
note = {Source note cucm-sip-trunk-no-service-troubleshooting-tls-fail-inference, checked 2026-10-02}
}