READ Free Dumps For Cisco- 400-051
| Question ID 12925 | Refer to the exhibit.
Which DTMF relay method is advertised when the originating SIP gateway sends an
INVITE message with a Call-Info header shown?
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| Option A | RFC 2833
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| Option B | SIP INFO
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| Option C | SIP NOTIFY
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| Option D | SIP KPML
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| Option E | In-band audio
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| Correct Answer | C |
Explanation Explanation: You can develop user-specific applications that reside on your network entity and have the ability to subscribe for event services supported by the IMG. If the network entity wants the ability to detect an entered DTMF digit (only telephone event of ### are currently supported) from the TDM-side of a call to the IP side of a call, the entity can subscribe to the IMG for these events and receive SIP NOTIFY events containing the digit event.
| Question ID 12926 | How are DTMF digits transported in RFC 2833?
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| Option A | In the RTP stream with the named telephone events payload format.
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| Option B | In the RTP stream with the regular audio payload format.
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| Option C | In SIP NOTIFY messages.
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| Option D | In SIP INFO messages.
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| Option E | In SIP SUBSCRIBE messages.
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| Correct Answer | A |
Explanation Explanation: DTMF digits and named telephone events are carried as part of the audio stream, and MUST use the same sequence number and time-stamp base as the regular audio channel to simplify the generation of audio waveforms at a gateway. The default clock frequency is 8,000 Hz, but the clock frequency can be redefined when assigning the dynamic payload type.