To prove a session-refresh drop, Cisco says to collect SIP logs from both sides and check four things: the refresher role in the initial INVITE, that a re-INVITE or UPDATE goes out before half the interval, that Unified CM relays it to the far side, and that responses come back.

Checked 2026-09-25

Vendor
Cisco
Product
Unified Communications Manager
Subsystem
troubleshooting
Deployment
on-premises
Region
not restricted
Release range
as documented 2015-07-23
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). Calls that drop after about 30 seconds: source note sip-calls-drop-30-seconds-cucm-refresh-trace-steps. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-calls-drop-30-seconds-cucm-refresh-trace-steps

BibTeX

@misc{warmtransfer-claim-sip-calls-drop-30-seconds-cucm-refresh-trace-steps,
  title  = {Calls that drop after about 30 seconds: source note sip-calls-drop-30-seconds-cucm-refresh-trace-steps},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-calls-drop-30-seconds-cucm-refresh-trace-steps},
  note   = {Source note sip-calls-drop-30-seconds-cucm-refresh-trace-steps, checked 2026-09-25}
}

Read in context