Comfort Noise Generation; Dual-Tone Multi-Frequency Signaling; Configuring Dtmf Transport Types - AudioCodes Mediant 3000 User Manual

The procedure below describes how to configure the jitter buffer using the Web interface.

To configure jitter buffer using the Web interface:
1. Open the RTP/RTCP Settings page (Configuration tab > VoIP menu > Media
submenu > RTP/RTCP Settings).
2. Configure the following parameters:
•
'Dynamic Jitter Buffer Minimum Delay' (DJBufMinDelay) - Defines the minimum
delay (in msec) for the Dynamic Jitter Buffer.
•
'Dynamic Jitter Buffer Optimization Factor' (DJBufOptFactor) - Defines the
Dynamic Jitter Buffer frame error/delay optimization factor.
3. Click Submit to apply your settings.

12.3.2 Comfort Noise Generation

The device can generate artificial background noise ("comfort" noise) in the voice channel
during periods of silence (i.e. no party is speaking). This is useful in that it reassures the
calling parties that the call is still connected. The device detects silence using its Voice
Activity Detection feature. When the CNG is enabled and silence is detected, the device
transmits Silence Identifier Descriptors (SIDs) parameters to reproduce the local
background noise at the remote (receiving) side.
The Comfort Noise Generation (CNG) support also depends on the silence suppression
(SCE) setting for the coder used in the voice channel. For more information, see the
description of the CNG-related parameters.
The procedure below describes how to configure CNG using the Web interface.

To configure CNG using the Web interface:
1. Open the RTP/RTCP Settings page (Configuration tab > VoIP menu > Media
submenu > RTP/RTCP Settings).
2. Set the 'Comfort Noise Generation' (ComfortNoiseNegotiation) parameter to Enable.
3. Click Submit to apply your changes.

12.3.3 Dual-Tone Multi-Frequency Signaling

12.3.3.1 Configuring DTMF Transport Types

The device supports various methods to transport DTMF digits over the IP network to the
remote endpoint. These methods and their configuration are described below:

Using INFO message according to Nortel IETF draft: DTMF digits are carried to the
remote side in INFO messages. To enable this mode, define the following:
•
RxDTMFOption = 0
•
TxDTMFOption = 1
Note that in this mode, DTMF digits are erased from the audio stream
(DTMFTransportType is automatically set to 0).

Using INFO message according to Cisco's mode: DTMF digits are carried to the
remote side in INFO messages. To enable this mode, define the following:
•
RxDTMFOption = 0
•
TxDTMFOption = 3
Note that in this mode, DTMF digits are erased from the audio stream
(DTMFTransportType is automatically set to 0 ).
SIP User's Manual 170
Mediant 3000
Document #: LTRT-89712