When a third-party SIP Phone System is dialed inbound across a Cisco Unified Border Element, DTMF is failing. The third-party vendor accepts only out-of-band DTMF. Which configuration should be added

The correct answer is D. dtmf-relay sip-kpml. The third-party vendor requires out-of-band DTMF, meaning DTMF digits must be signaled separately from the RTP audio stream. On a Cisco CUBE outgoing dial peer, 'dtmf-relay sip-kpml' uses SIP KPML (Keypad Markup Language), which conveys DTMF via SIP SUBSCRIBE/NOTIFY messages enti

Cisco Unified Border Element

Question

When a third-party SIP Phone System is dialed inbound across a Cisco Unified Border Element, DTMF is failing. The third-party vendor accepts only out-of-band DTMF. Which configuration should be added to the outgoing dial peer to resolve this issue?

Options

Adtmf-relay rtp-nte
Bdtmf-relay cisco-rtp
Cdtmf-relay h245-signal
Ddtmf-relay sip-kpml

How the community answered

(37 responses)

A
3% (1)
B
5% (2)
C
11% (4)
D
81% (30)

Explanation

The third-party vendor requires out-of-band DTMF, meaning DTMF digits must be signaled separately from the RTP audio stream. On a Cisco CUBE outgoing dial peer, 'dtmf-relay sip-kpml' uses SIP KPML (Keypad Markup Language), which conveys DTMF via SIP SUBSCRIBE/NOTIFY messages entirely in the SIP signaling plane-completely out of band from the media stream. 'dtmf-relay rtp-nte' (RFC 2833) embeds DTMF as named telephone events inside the RTP stream, which some systems consider in-band. 'dtmf-relay h245-signal' is an H.323 mechanism and does not apply to SIP, and 'dtmf-relay cisco-rtp' is a Cisco proprietary method unlikely to be supported by a third party.

Topics

#DTMF Relay#Cisco CUBE#SIP Signaling#Dial Peer

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