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These features are configured in the IMG 1010 - IP Bearer Profile pane

 Silence Silence Suppression:

During a normal voice conversation, much of the time is wasted on silence from one or both ends. Ethernet bandwidth can be conserved if during these periods of silence RTP packets are sent with silence-encoded compressed payloads. The IMG Silence Suppression feature supports the concepts of Voice Activity Detection (VAD) and Comfort Noise Generation (CNG). When enabled Silence suppression will not send RTP traffic during periods of silence, saving bandwidth usage. At the beginning of a silence period, a single packet will be sent to the distant end to inform it that a period of silence is being entered, and that the distant end should begin to regenerate comfort noise to its TDM stream. Silence Suppression can be enabled or disabled on an established connection.

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See the Fax Mode and Fax Bypass Codec fields in the IMG 1010 - IP Bearer Profile pane.

Fax Packet Redundancy:

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See the Fax Mode and Fax Packet Redundancy fields in the IMG 1010 - IP Bearer Profile pane.

Modem Bypass:

If this feature is enabled the IMG switches to another codec when you are in a modem call. The codec that you switch to is specified in the Fax Bypass Codec field. For example, if you are using a low bit rate codec, such as G.729, a modem or fax call will probably not be successful. So in this case the IMG changes the codec to what is configured in the Fax Bypass Codec field.

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See the Modem Behavior field in the IMG 1010 - IP Bearer Profile pane.

Modem Disable:

If Modem Behavior is set to Disabled and Fax Mode is set to 'Enable Relay (T.38)', any detected data is assumed to be T.38 fax related. RTP will be shut down and then T.38 protocol will be started.

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The IMG can propagate DTMF digits as In-Band, Packetized or via H.245 UII. The packet type can be changed for digit relay. See the Digit Relay and Digit Relay Packet Type fields in the IMG 1010 - IP Bearer Profile pane.

If the Digit Relay field in the IP Bearer profiles object pane is set to DTMF Packetized then the telephone event message will be sent in the CDR otherwise the telephone event message will not be sent. See below

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The Media Inactivity feature was added to the IMG to inform the signaling layers (SIP and H323) when RTP has stopped flowing. The Initial Media Inactivity timer indicates that no RTP was ever received on the IP channel. The Media Inactivity Timer indicates that RTP has stopped flowing. When the signaling layers receive indications that these timers have expired, the signaling releases the channel. This feature resolves the problem where signaling gets out of sync and IP channels remain up with no one on the other side of the call. See IMG 1010 - Media Inactivity Timers (RTP) link.

RTP Change Upon Gratuitous ARP (10.5.0 ER2):

In Feature F-1485 the IMG will use Ethernet information sent in a Gratuitous ARP from a Network Cluster to determine if the IP address information in the RTP streams going to and from the IMG needs to be updated. See IMG 1010 - RTP change on Gratuitous ARP link.

Clear Channel Codec RFC 4040:

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