Cisco's proprietary cisco-rtp DTMF relay (payload type 121) has been discontinued on CUBE.

Checked 2026-09-24

Vendor
Cisco
Product
Cisco Unified Border Element
Subsystem
dtmf-relay
Deployment
on-premises
Region
not restricted
Release range
IOS XE 17.6 onwards
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). DTMF methods and interoperability failures: source note dtmf-interop-cube-cisco-rtp-discontinued. WarmTransfer. https://warmtransfer.net/knowledge/claims/dtmf-interop-cube-cisco-rtp-discontinued

BibTeX

@misc{warmtransfer-claim-dtmf-interop-cube-cisco-rtp-discontinued,
  title  = {DTMF methods and interoperability failures: source note dtmf-interop-cube-cisco-rtp-discontinued},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/dtmf-interop-cube-cisco-rtp-discontinued},
  note   = {Source note dtmf-interop-cube-cisco-rtp-discontinued, checked 2026-09-24}
}

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