Troubleshooting guide

Epygi Technologies Hidden Pages for Quadro Advanced Configuration
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Short DTMF pulse suppression: (not available in Quadro2x’s) Enables short in-band DTMF
suppression received from the remote endpoint when the out-of-band DTMF support is
negotiated. Enabling this checkbox is recommended if the Quadro is used as a gateway
between a SIP and non-SIP endpoints and the non-SIP endpoint detects short DTMFs (less
than 20 ms) as valid DTMFs, resulting in, for example, double detection of DTMFs. In-band
DTMFs shorter than 35-40 ms are normally ignored.
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CNG (Comfort Noise Generation): A technique used in codecs to generate an artificial noise if
no voice packet or a CN packet is received from the remote party. With typical PSTN networks
people are accustomed to hearing a very low level of background noise on a call. Without
Comfort Noise packets being locally generated by the Quadro or far-end there would be
complete silence on the call when a person is not speaking and the other party would think the
call was disconnected.
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Extrapolation: A technique used in codecs to recover a lost or delayed RTP packet to provide
a seamless voice experience to the user.
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Telephone Event Draft Support: Enables out-of-band DTMF transmission according to the
draft-ietf-avt-rfc2833bis-04 (RFC 4733).
To disable the CNG or Extrapolation option for a codec, select the codec and click on Edit (see
Figure 3). Clear the checkbox for the appropriate option and click on Save.
Figure 2 Voice Codecs Settings page
PAGE 6 17-Feb-15