When both unsolicited NOTIFY and NTE are negotiated on SIP, Cisco IOS chooses unsolicited NOTIFY and suppresses the in-band RFC 2833 NTE packets to avoid double tones.
Checked 2026-10-02
When both the UN and NTE methods are negotiated, Cisco IOS always chooses UN over NTE to avoid double tones and In-band 2833 NTE packet is suppressed.
- Vendor
- Cisco
- Product
- Cisco Unified Border Element
- Subsystem
- DTMF relay
- Deployment
- on-premises
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- Configure DTMF Relay on CUBE — Cisco Systems · tier 2 current vendor documentation · SIP section on preference when multiple DTMF methods are negotiated
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting DTMF digits not detected in Webex Contact Center flows: source note wxcc-dtmf-troubleshooting-un-over-nte. WarmTransfer. https://warmtransfer.net/knowledge/claims/wxcc-dtmf-troubleshooting-un-over-nte
BibTeX
@misc{warmtransfer-claim-wxcc-dtmf-troubleshooting-un-over-nte,
title = {Troubleshooting DTMF digits not detected in Webex Contact Center flows: source note wxcc-dtmf-troubleshooting-un-over-nte},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/wxcc-dtmf-troubleshooting-un-over-nte},
note = {Source note wxcc-dtmf-troubleshooting-un-over-nte, checked 2026-10-02}
}