Source note · DTMF methods and interoperability failures
In-band DTMF is recognised reliably only on G.711 (ulaw or alaw); low-bit-rate codecs distort the tones so they may not be recognised.
Checked 2026-09-24
- Vendor
- multi-vendor
- Product
- in-band audio DTMF
- Subsystem
- codec
- Deployment
- any
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- Configure DTMF Relay on CUBE — Cisco Systems · tier 2 current vendor documentation · Common issues: codec distortion / G711 requirements
Cite this note
APA
WarmTransfer. (2026, September 24). DTMF methods and interoperability failures: source note dtmf-interop-inband-codec-distortion. WarmTransfer. https://warmtransfer.net/knowledge/claims/dtmf-interop-inband-codec-distortion
BibTeX
@misc{warmtransfer-claim-dtmf-interop-inband-codec-distortion,
title = {DTMF methods and interoperability failures: source note dtmf-interop-inband-codec-distortion},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/dtmf-interop-inband-codec-distortion},
note = {Source note dtmf-interop-inband-codec-distortion, checked 2026-09-24}
}