Coder Parameters

'SILK Tx Inband FEC'

configure voip > media settings > silk-tx-inband-fec

[SilkTxInbandFEC]

Enables forward error correction (FEC) for the SILK coder.

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[0] Disable (default)

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[1] Enable

'SILK Max Average Bit Rate'

configure voip > media settings > silk-max-average-bitrate

[SilkMaxAverageBitRate]

Defines the maximum average bit rate for the SILK coder.

The valid value range is 6,000 to 50,000. The default is 50,000.

The SILK coder is Skype's default audio codec used for Skype-to-Skype calls.

configure voip > media settings > vbr-coder-header-format

[VBRCoderHeaderFormat]

Defines the format of the RTP header for VBR coders.

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[0] = (Default) Payload only (no header, TOC, or m-factor) - similar to RFC 3558 Header Free format.

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[1] = Supports RFC 2658 - 1 byte for interleaving header (always 0), TOC, no m-factor.

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[2] = Payload including TOC only, allow m-factor.

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[3] = RFC 3558 Interleave/Bundled format.

configure voip > media settings > vbr-coder-hangover

[VBRCoderHangover]

Defines the required number of silence frames at the beginning of each silence period when using the VBR coder silence suppression.

The range is 0 to 255. The default is 1.

'AMR Payload Format'

[AmrOctetAlignedEnable]

Defines the AMR payload format type.

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[0] Bandwidth Efficient

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[1] Octet Aligned (default)

Note: The AMR payload type can also be configured per Coder Group (see Configuring Coder Groups). The Coder Group configuration overrides the parameter.

configure voip > media settings > amr-header-format

[AMRCoderHeaderFormat]

Defines the payload format of the AMR header.

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[0] = Non-standard multiple frames packing in a single RTP frame. Each frame has a CMR and TOC header.

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[1] = AMR frame according to RFC 3267 bundling.

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[2] = AMR frame according to RFC 3267 interleaving.

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[3] = AMR is passed using the AMR IF2 format.

Note: Bandwidth Efficient mode is not supported; the mode is always Octet-aligned.

'Fax/Modem Bypass Packing Factor'

configure voip > media fax-modem > packing-factor

[FaxModemBypassM]

Defines the number (20 msec) of coder payloads used to generate a fax/modem bypass packet.

The valid range is 1, 2, or 3 coder payloads. The default is 1 coder payload.

'Transparent on Data Call'

[TransparentCoderOnDataCall]

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[0] Disable = (Default) Only use coders from the coder list.

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[1] Enable = Use Transparent coder for data calls (according to RFC 4040).

The Transparent coder can be used on data calls. When the device receives a Setup message from the ISDN with 'TransferCapabilities = data', it can initiate a call using the coder 'Transparent' (even if the coder is not included in the coder list).

The initiated INVITE includes the following SDP attribute:

a=rtpmap:97 CLEARMODE/8000

The default payload type is set according to the [CodersGroup] parameter. If the Transparent coder is not defined, the default is set to 56. The payload type is negotiated with the remote side, i.e., the selected payload type is according to the remote side selection. The receiving device must include the 'Transparent' coder in its coder list.

Note: The parameter is applicable only to digital interfaces.

configure voip > sip-definition settings > transparent-payload-type

[TransparentPayloadType]

Defines the payload type of the Transparent coder for outgoing data calls (ISDN-to-IP).

When the device receives a Setup message from the ISDN with 'TransferCapabilities = data', it can initiate a call using the coder 'Transparent' (even if the coder is not included in the coder list).

The initiated INVITE includes the following SDP attribute:

a=rtpmap:97 CLEARMODE/8000

The valid value range is 1 to 127. The default value is 56.

Note: The parameter is applicable only to digital interfaces.