In Unified CM, OPTIONS Ping is enabled on the SIP Profile (Device > Device Settings > SIP Profile) assigned to the SIP trunk, and the CUBE side uses voice-class sip options-keepalive on the dial peer.

Checked 2026-09-25

Vendor
Cisco
Product
Unified Communications Manager
Subsystem
SIP trunk OPTIONS ping
Deployment
on-premises
Region
not restricted
Release range
as documented in 2019 tech note
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP 503 and trunk out-of-service failures: source note sip-503-trunk-failures-cucm-enable-sip-profile. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-503-trunk-failures-cucm-enable-sip-profile

BibTeX

@misc{warmtransfer-claim-sip-503-trunk-failures-cucm-enable-sip-profile,
  title  = {SIP 503 and trunk out-of-service failures: source note sip-503-trunk-failures-cucm-enable-sip-profile},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-503-trunk-failures-cucm-enable-sip-profile},
  note   = {Source note sip-503-trunk-failures-cucm-enable-sip-profile, checked 2026-09-25}
}

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