IPCC 4.5 - DTMF from 3rd party H.323

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Nov 15th, 2007
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I have problem, when I'm calling to IPCC IVR from non ip phone through VoIP device defined as H.323 gateway in Communication Manager 5.1 the DTMF digits are not recognized.

This gateway doesn't have capability of DTMF relay. In the same network I have Cisco mgcp gateways, DTMF digits coming from non IP phones through these gateways without problem. How to get it working together?

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vmoopeung Wed, 11/21/2007 - 15:09
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Cisco Unified CallManager requires an RFC 2833 DTMF-compliant MTP device to make SIP calls. The current standard for SIP uses inband payload types to indicate DTMF tones, and Cisco Unified Communications components such as SCCP IP phones support only out-of-band payload types. Thus, an RFC 2833-compliant MTP device monitors for payload type and acts as a translator between inband and out-of-band payload types.

With the MTP device, any service that requires a media change (such as call hold) happens transparently. No need exists to send any media update signal to the SIP proxy server.



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