A trunk can show No Service while utils network ping to the peer succeeds, because OPTIONS ping also fails on 503 or 408 answers, on TCP connect failure and on a wrong destination port, none of which ICMP tests.
inferred · Checked 2026-10-02
- Vendor
- Cisco
- Product
- Unified Communications Manager
- Subsystem
- SIP trunk troubleshooting
- Deployment
- on-premises
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Status
- inferred
- Checked
- 2026-10-02
Sources
- Cisco Unified Communications Manager Trunks (Session Management Edition deployment guide, Release 8.5(1)) — Cisco Systems · tier 2 current vendor documentation · SIP OPTIONS Ping (combined with technote 213718 Troubleshoot section)
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-reachable-but-oos. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-sip-trunk-no-service-troubleshooting-reachable-but-oos
BibTeX
@misc{warmtransfer-claim-cucm-sip-trunk-no-service-troubleshooting-reachable-but-oos,
title = {Troubleshooting Unified CM SIP trunks that show No Service: source note cucm-sip-trunk-no-service-troubleshooting-reachable-but-oos},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-sip-trunk-no-service-troubleshooting-reachable-but-oos},
note = {Source note cucm-sip-trunk-no-service-troubleshooting-reachable-but-oos, checked 2026-10-02}
}