Source note · SIP 503 and trunk out-of-service failures
With OPTIONS Ping enabled, each Unified CM node running the trunk's SIP daemon periodically pings each destination and sends calls only to reachable destinations, instead of discovering failures per call through timeouts.
Checked 2026-09-25
- Vendor
- Cisco
- Product
- Unified Communications Manager
- Subsystem
- SIP trunk OPTIONS ping
- Deployment
- on-premises
- Region
- not restricted
- Release range
- stated in the 8.6(1) SME design guide; later releases not verified from a fetched document
- Checked
- 2026-09-25
Sources
- Cisco Unified Communications Manager Trunks (Session Management Edition deployment guide 8.6(1)) — Cisco · tier 2 current vendor documentation · Subsection 'SIP OPTIONS Ping'
Cite this note
APA
WarmTransfer. (2026, September 25). SIP 503 and trunk out-of-service failures: source note sip-503-trunk-failures-cucm-calls-reachable. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-503-trunk-failures-cucm-calls-reachable
BibTeX
@misc{warmtransfer-claim-sip-503-trunk-failures-cucm-calls-reachable,
title = {SIP 503 and trunk out-of-service failures: source note sip-503-trunk-failures-cucm-calls-reachable},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-503-trunk-failures-cucm-calls-reachable},
note = {Source note sip-503-trunk-failures-cucm-calls-reachable, checked 2026-09-25}
}