Specifications

Chapter 10 - Voice Transmissions Enabling Individual Codecs
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Mediatrix 4100
Enabling Individual Codecs
Enabling individual codecs allows you to define codecs that can be considered during negotiation. If codecs
are disabled, they are not considered.
 To enable voice codecs:
1. In the voiceIfMIB, choose the codec you want to use (voiceIfCodecTable).
You have the choice between the following codecs:
2. If you have enabled one or more of the G.726 codecs, set the G.726 actual RTP dynamic payload
type used in an initial offer in one or more of the following variables:
• voiceIfCodecG72616kbpsPayloadType: The default value is 97.
• voiceIfCodecG72624kbpsPayloadType: The default value is 98.
• voiceIfCodecG72632kbpsPayloadType: The default value is 99.
• voiceIfCodecG72640kbpsPayloadType: The default value is 100.
The payload types available are as per RFC 3551. The values range from 96 to 127.
3. Restart the Mediatrix 4100 so that the changes may take effect.
Table 99: Enabling Voice Codecs
Codec Variable Set to...
PCMU (G.711 u-Law) voiceIfCodecPcmuEnable enable
PCMA (G.711 a-Law) voiceIfCodecPcmaEnable enable
G.723.1 voiceIfCodecG723Enable g723-53kbs
g723-63kbs
G.726 at 16 kbps voiceIfCodecG72616kbpsEnable enable
G.726 at 24 kbps voiceIfCodecG72624kbpsEnable enable
G.726 at 32 kbps voiceIfCodecG72632kbpsEnable enable
G.726 at 40 kbps voiceIfCodecG72640kbpsEnable enable
G.729.A voiceIfCodecG729Enable enable
Note: When selecting the dynamic payload type, make sure that the value is not already used by another
dynamic codec. If a value between 96 and 127 is refused, this means it is already used by another dynamic
codec.
Note: If you set the voiceIfDtmfTransport variable to outOfBandUsingSignalingProtocol (“DTMF
Transport Type” on page 139), you cannot configure a dynamic payload type to 111 because it is already
used by the DTMF out-of-band using signalling protocol.