In a hairpin call through CUBE, neither the caller nor the called party sends RTP until it receives RTP from something in the call path. Cisco calls this a deadlock, and the result is no-way audio.

Checked 2026-09-24

both, the call initiator and the call receiver don't send any streams unless they receive a stream from someone in the path of the call, this is a deadlock situation
Vendor
Cisco
Product
Cisco Unified Border Element
Subsystem
hairpin media
Deployment
on-premises
Region
not restricted
Release range
technote 214622, updated 2023-07-18
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). One-way and no-way audio diagnosis: source note one-way-audio-hairpin-deadlock. WarmTransfer. https://warmtransfer.net/knowledge/claims/one-way-audio-hairpin-deadlock

BibTeX

@misc{warmtransfer-claim-one-way-audio-hairpin-deadlock,
  title  = {One-way and no-way audio diagnosis: source note one-way-audio-hairpin-deadlock},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/one-way-audio-hairpin-deadlock},
  note   = {Source note one-way-audio-hairpin-deadlock, checked 2026-09-24}
}

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