Source note · DTMF methods and interoperability failures
Unified CM inserts an MTP when a SIP endpoint supports only RFC 2833 and the other side needs out-of-band DTMF; the MTP exchanges RFC 2833 packets with the SIP endpoint and out-of-band DTMF with Unified CM.
Checked 2026-09-24
- Vendor
- Cisco
- Product
- Cisco Unified Communications Manager
- Subsystem
- media resources
- Deployment
- on-premises
- Region
- not restricted
- Release range
- as of 2015-01-09 technote; release not stated
- Checked
- 2026-09-24
Sources
- CallManager/ DTMF/ MTP Allocation — Cisco Systems · tier 2 current vendor documentation · DTMF/MTP allocation table and explanation
Cite this note
APA
WarmTransfer. (2026, September 24). DTMF methods and interoperability failures: source note dtmf-interop-cucm-mtp-for-mismatch. WarmTransfer. https://warmtransfer.net/knowledge/claims/dtmf-interop-cucm-mtp-for-mismatch
BibTeX
@misc{warmtransfer-claim-dtmf-interop-cucm-mtp-for-mismatch,
title = {DTMF methods and interoperability failures: source note dtmf-interop-cucm-mtp-for-mismatch},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/dtmf-interop-cucm-mtp-for-mismatch},
note = {Source note dtmf-interop-cucm-mtp-for-mismatch, checked 2026-09-24}
}